Eduweb's Adventures

http://www.eduweb.com/portfolio/adventure.php
Eduweb help create great educational websites for a whole range of clients. This page on their website allows you to browse their portfolio of projects by subject or age group. It's a US site so everything is listed by grade (see this page on our site for a conversion table) but there's plenty of material that's great UK teachers and students. I've recently been exploring some of the brilliant visual arts websites.