I started a bit of stupid fun on Twitter: #webappcelebs. Some of my favorites so far:
Eddie Van Hahlo
Paul Reubens on Rails
Google Lou Reader
Sid Del.ico.us (also: Benicio Del.ico.us)
AIM Judy Dench
And I can’t find it, but I swear I saw someone do Lucy Hululiu, which seems so much funnier that just Lucy HuLiu for some reason.