Blox.com [formerly halfbrain.com]:
Still an amazing site several years after its debut. Check
out blox.com's browser-based spreadsheet and presentation
program. [sorry, Blox.com is
now defunct] 
The
Register: Irreverent and relevant stuff for geeks (and
would-be geeks). What can you say about a site whose tag line
is, "Biting the hand that feeds IT?"
Emergic.org:
Rajesh Jain's Weblog on Emerging Technologies, Enterprises
and Markets. A great blog/newsletter with key news and insights
of the day.
The
VC: Tales from the Internet
Era. A comic strip by and about VC's. Funny... and in some
ways, painful.
Map.net:
An interesting way to categorize and visualize web sites.
Measuring
Success: A great synopsis of the goals and methodologies
of online advertising. From the Internet Advertising Bureau's
site [iab.net].
Zoomerang:
THE easiest, smoothest, best way to do surveys on the web.
TechCalendar:
Find every technology trade show ever [that's scary].
OddPost:
An amazing, next generation dhtml mail application created
by ex-halfbrain engineers Ethan Diamond & Iain Lamb, assisted
by Shawn Grunberger and Don Vail.
The
Onion, Satirewire,
Modern
Humorist, Dave
Barry: Four sites that, themselves, justify the existence
of the Internet.
The
Web Economy BS Generator: An essential tool for those
of us working in Marketing.
Davenet:
Egotistical, opinionated, wrong-headed... Dave Weiner isin
some waysthe Rush Limbaugh of web journalism. But his
stuff is always relevant and often important.