Librarian Chick is a blogger who has put together a wiki of literally hundreds of online learning sources with over twenty categories for "students, educators & anyone else who's hip to learning." [more inside]
Learn to Play Guitar! Justin, of JustinGuitar.com (not the dork with the TV camera strapped to his head) offers over 100 free video guitar lessons for absolute noobs & guitar enthusiasts, with lesson categories & written instrx as well. For people who want tablature to play along, the good people of Guitar Video Tabs provide full tab notation under videos hundreds of popular songs.
The Imperial History of the Middle East is a flash based map of the Middle East, with a sliding timeline showing the various forces that have established dominance in the region over the last 5,000 years. Just one of many interesting interactive demonstrations over at Maps Of War.