A large online store that started out just selling books; nowadays, there is little it doesn't sell.
ToothyWiki can make links to Amazon UK items. When you hit on such a link, you get a preview page ("you clicked on..."); if you hit the "add to basket" button on that page, toothycat.net gets a large chunk (15% for books; it varies for other stuff) of what you pay. So if you're gonna buy stuff from Amazon anyway and don't have someone else you're already supporting like this, buy it through here and support us - it won't cost you any extra cash, just a little time :)
How to link to Amazon items:
Find the item on Amazon
Look for the ASIN or ISBN number (10 letters/digits) in the description
Copy and paste it into the wiki, prefixing it with "ASIN:" or "ISBN:" as appropriate.