Hey there,
So I didn't even see this message until today lol. So sorry for the delay.
This was a few trace effects in GIMP, then I colored the results. There was a LOT of editing involved lol. Here's the screens I made of comic art:
Retro Comic Android by *melissapugs on deviantART
Here's the tuts I looked at:
GIMP - Sketch Effect
Article - Apply Halftone Effects in Gimp
halftone effect in gimp by *istarlome on deviantART
Another tut was taken offline! Wow, I hope I can remember how to do it lol. Anyway, let me know if you need anything else via PM or GTalk, since I don't get notifications on these cool little profile posts -M