Oh, there's MUCH more. Especially during the Speed Beer arc.
EDIT: Let's see if I can track these down...
- 171 - Lil' Sis and Clango from Diesel Sweeties
- 511 - Davin and PeeJee (or is that Nancy?) from Something Positive
- 519 - Amy and Shelley from Scary Go Round
- 653 - (Technically) McPedro from Girls With Slingshots (he's on Raven's t-shirt)
- 855 - Eve from AppleGeeks
- 1246 - SEVERAL "Cameos": Rich Stevens, Meredith Gran; Holly Laing (?), Jon Rosenberg (?); Wil Wheaton, Rene Engstrom, Jon Rosenberg
- 1389 - The Speed Beer Arc: Jeph states he drew some of his friends in the background - including, once again,
Wesley Crusher Wil Wheaton. - 1391 - MOAR CAMEOS! Jamie and Hazel from Girls with Slingshots; Kimiko Ross from Dresden Kodak; Eve Ning from Octopus Pie; Anders von Silfersked (?) from Anders Loves Maria; Indie-rock Pete(?) from Diesel Sweeties; Jam (Angela) from Wasted Talents; Conrad and Ananth from Johnny Wander; there are at least two other characters that I can't quite ID.
- 1550 - Amber O'Malley from Shortpacked! (Dave Willis did a "parallel strip" where Faye said her line in a different coffee shop)
(This list obviously does NOT include guest strips, by the way.)
Anyone who wants to help out with some of the others, feel free.
EDIT: I'm not entirely sure who Jeph was talking about in 1246. I still say the third panel looks more like Danielle and Randy...