A great site for seeing how websites are put together. Drag the 'X-ray Goggle' button into your favourites bar and click to see the coding of a site. Then you can edit the code to make changes and publish online.
http://ictmagic.wikispaces.com/ICT+%26+Web+Tools
Mess around with web pages. This is from David Warlick's post on Educon that I posted as part of the daily news. You're not REALLY changing the page but changing it locally on your machine, but is is still a lot of fun. There are also links to using this site to teach how to make websites.