NaNoWriMo - Would-be novellists, join us! Every November we masochists attempt a 50,000 word novel in the space of 30 days. It's painful, it's horrific and it's unreadable, but by god it's fun.
Boy Meets Boy - One of the best and consistently clever webcomics. It's got punk, gay and Satan. What more do you need?
Friendly Hostility - By the same author as BMB. It's not quite up to the same stellar heights, but it can kick your posterior any day.
JSesh - A free typesetter for Egyptian Hieroglyphs. It's by far the best program of its kind, free or otherwise. It is cross-platform, very easy to use, has a huge range of available glyphs and has the ability to import more. It exports into word processors, PDF and HTML. It's streets ahead of Glyph for Windows, which has not been significantly altered since the Windows 3.1 version (yet the makers still seem to like charging thousands of dollars for it).
Chicken Nation - The glorious home to Raymondo Person, Pink Chickens and Tobias and Jube. Feel the unmittigated genius! Go there, inject orange juice, and fear the Wraith.
Dresden Codak - Beautiful. Just... beautiful. I never thought someone would manage to combine so much philosophy, science and transrealism into the one comic, not to mention the razor sharp dialogue and witty one-liners. It's just all there, in one amazingly well-drawn package.
xkcd - A webcomic of romance, sarcasm, math and language.
Lackadaisy - A webcomic about several bootleggers trying to make a dishonest living in the Depression. The art style in this webcomic is unspeakably clever and detailed, and the artist's comic timing is second to none. This is destined to be a modern classic.