Random useful and interesting sites

Found via StumbleUpon:

* Google sightseeing — a great way to see satellite photos of interesting world sites
* Test everything — a jillion tools for testing the construction, seo, and other characteristics of your site
* Computer Architecture — a one page primer walking you up from gates through to a complete simple computer.
* graph paper creator.
* Codswallop — one person’s view on the 100 simple web apps you need