My favorite site on the web right now is muxway, which Joshua Schachter has created as a database of (just barely) categorized links. You know Joshua's work from the venerable memepool, but this site might be even better.
To view the list by category, just click the category name after one of the links. They're self-explanatory, except that "tl" stands for timeline, which is a big timeline of computing that is still a work in progress.
Caution: Do not follow the link to muxway if you have any deadlines looming. You have been warned.