Being green doesn't have to mean being vegetarian or vegan (although there are some persuasive arguments) but I think I'm not mistaken in thinking that a sizeable chunk of Hippyshopper readers fall into one of those two camps. On which assumption, quite a few of you must now be feeling as unimpressed as I am that Mars chocolates will no longer be vegetarian from October. So other than stockpiling Milky Ways, what can you do?

It seems to me that Masterfoods had under-estimated the power of the vegetarian voice when they chose to make this untimely decision; already arch-rival Cadbury is drawing attention to the vegetarian society logo its products now carry. The society itself has thrown its weight behind the cause of retaining the rennet-free Mars bar as part of its Imperfect World campaign, where you'll find a selection of online lobbying tools to get the message through. Otherwise, you could always use the Masterfoods feedback form to express your displeasure.

Related: National Vegetarian Week 21st-27th May 2007 | No more Mars bars for veggies

Chris Goodall's take on preventing climate change is that it's too important to be left to governments and corporations - each of us needs to do our part individually to reduce our carbon emissions.

In his book, 'How to live a low-carbon life' (currently available for £14.24 from amazon), Goodall lays out tips on how to do exactly that, dealing with everything from tumble dryers to public transport. To keep you up to date with all the latest news, there's also a website to accompany the book.

Related: Rubbish! book by Richard Girling | Plant some trees, get climate book cheaper

Wouldn't it be great if all the world's problems could be solved by blogging? If all we had to do was type our grievences about the state of the planet into a little box in one big rant, hit 'post' and wait for some wise anonymous commenter to give us all the answers?

Maybe it's not going to work like that, but we can dream, and I was inspired by this list compiled by Valleywag, with suggestions for '10 online ways to save the world' - so I've come up with a similar list for Hippyshopper: Hippyshopper's top 10 sites to make the world a better place

1. Click4thecause: Until the end of this month, every time you use this search engine instead of your usual one, you'll be donating to ninemillion, a UN campaig set up to help the 9 million children worldwide who are living as refugees. There's some more info on this wonderful idea here.

2. We are what we do. Very slick-looking site crammed full of tips both big and small on making the world a happier place. Helps kick-start your good intentions, and lets you track your good deeds.

3. The Hunger Site. The original free 'click to donate' site that's still going strong. And don't forget, you can also donate to breast cancer research, underpriviledged kids, animal shelters and rainforest conservations projects while you there.

4. ChanceXchange: chanceXchange is a free service where you can trade unwanted films, cds and books for those things that you really want. Earn double brownie points for the fact that you're not only reusing and reducing waste, but you're also making someone's day by offering that unwanted Backstreet Boys album they've been coveting for years.

5. E-Cards. Sending an e-card for a friend's birthday is a good way to avoid the wastage of sending paper cards through the post. And they're not all as naff as you might have feared. Have a browse though this site for some really imaginative designs, including stunning wildlife photography.

Climate change charity Global Cool are up to their old tricks again, and have come up with another nifty planet saving campaign, launching tomorrow. This one will combine the three mighty forces of Myspace, text messaging and celebs.

Led by a galaxy of stars including Sienna Miller, Josh Hartnett and Rosario Dawson, the campaign provides simple tips via SMS on how to personally reduce your carbon footprint, with all proceeds going to the charity. Visit Global Cool's Myspace page tomorrow to be there when it all happens.

Related stories: Donate a tonne to Global Cool

Google employees are being given free bicycles to help reduce the environmental impact of their travel to work. The company has also installed solar panels at its HQ to provide green energy.

Although I'll ask, I think it's unlikely my employer will give me a bike. The story has made me think though: a lot of people spend more time at the office than at home, so what can companies do to lessen their environmental impact?

Ecover has recently teamed up with the Stop Climate Chaos Coalition to give you the chance to win a green spring clean for your home, a copy of Ecover's Healthy Homes book, and a copy of the coalition's I count book - all you'll need to ensure your home gets green-clean and stays that way! Instructions on how to enter will be on Ecover's products in coming weeks. Ecover is also interested in your views on being green, and your attitudes towards green living. Why not complete the survey here, and give them some ideas on the sort of green products you would like to see on the shelves?

It seems our parents' attempts to make us 'think of the starving children' when we left food on our plates were all in vain: Britons, we learnt today, throw away a third of our food, equating to 6.7 million tonnes every year.

I know I'm as guilty as the next Brit, especially since I often cook for myself but still buy family packs of bread, vegetables and other perishable items out of sheer laziness. So I've come up with a few tips on how to reduce your food waste. Please feel free to suggest more!

1. Pay attention to use-by dates on the food you buy. It's not unusual for supermarkets to put new stock next to stuff that's almost past its sell-by. Taking a few seconds to check this means you'll throw out a lot less. You might also want to invest in some re-sealable containers for keeping food fresh for longer.

2. Get a wormery, and turn your rubbish into high quality compost. Worms won't eat all your food waste (citrus and onions are a no-no) but once you've cut down the amount you buy, you can start feeding your wriggly friends vegetable peelings, old fruit, leftover pasta, rice and even small amounts of meat, and they'll soon be happily churning out plant feed. Wormcity sell them from just £20.

I've bought several reusable plastic bags over the last year and, some how, I've never got round to actually reusing them. Instead they've been folded neatly and left in the kitchen. Utterly useless. However, at the beginning of last week as I popped into Asda's for my daily 'I've forgotten something from the weekly shop' catch up, I remembered to pick one up. The day before, you see, I'd used two plastic bags and promptly thrown them in the bin afterwards. I realised if I did that five times a week on random items then I could use up to 10 bags per week. And if I used that volume every week, it was entirely likely I could use 520 plastic bags per year.

Debate continues to rage over the government's plans to go ahead with a new generation of Trident missiles, with the news today that Nigel Griffiths, deputy leader of the Commons, has quit the government ahead of Wednesday's vote on the renewal plan.

If you'd like to add your voice to the growing number concerned about the Trident replacement issue, which is detailed on the CND site, there are already a lot of petitions and protests to get involved with, many of them accessible from your desk. Designer Katherine Hamnett of choose life fame is leading a letter writing campaign at her website, which provides all the info you'll need to lobby your MP, but you've only got one more day to do it. If you want to be closer to the action, however, CND will be holding an emergency lobby of parliament on the day of the vote.

Doing my weekly 'big shop' this weekend, I think I counted two other people reusing carrier bags. And despite the racks of bags-for-life and notices on every aisle promising brownie points for bringing your own bag, I still had to fight the shop assistants' attempts to put my groceries in a plastic bag at the checkout.

So I was heartened to see that someone's started this online campaign to get more people into the habit of having a shopper-bag on them at all times. Carry on Carriers set weekly 'challenges' to readers, and have produced this lovely little video which I think should be a compulsory part of checkout training...

There are 9 million children on this planet who are refugees. Of the 6 billion people alive on Earth today, 2.1 billion of them are children. If you can't do the maths, by our calculations that means that 0.4% of the world's children - or nearly one in every 200 - are refugees.

In an attempt to do our part to help combat this problem, Hippyshopper is taking part in Click4theCause, a collaboration between the United Nations High Commissioner for Refugees and Microsoft.

For every web search made using Click4theCause, Microsoft will donate money to the ninemillion.org campaign, which provides refugee children with education and sports programmes.

Black rhinos are among the most endangered species in the world, but their number went up by one on Monday when Sita, a rhino at Devon's Paignton Zoo, gave birth live on webcam.

If cooing over the baby rhino has you wondering what you can do to help endangered species (other than naming the calf), check out the latest book from natural collection.

[Louise Penman]

This site is a real gem, and a must-see for anyone who's ever been seized by the desire to do something to make the world a better place but not known where to start. From the people behind Change the World for a Fiver, We Are What We Do describes itself as 'a new movement dedicated to inspiring people to use their everyday actions to change the world', and just browsing it made me feel much more empowered and positive about my own, individual impact.

It's crammed full of tips, and includes an 'actions tracker' that rewards you for good deeds and allows you to keep tabs on how well you're doing towards changing the world. In this respect, it's a bit like a cross between Brownies and Danny Wallace's Random Acts of Kindness.

Join the BBC's Nest Box Challenge and help the British Trust for Ornithology (BTO) with its wild bird survey.

You can make your own box (instructions on the site), or pick up a free kit at one of the BBC nest box events being run around the country on the 17th and 18th of February.

Once you've got your bird home installed, click here to register it and then see who moves in...

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