Hm...I actually prefer powerpoint to make this comic. It's simple, easy and quick. If I want to do introquite photo editing...I use pixlr. I might check out paint.net or ipiccy. (photoshop and gimp is another story)
And i only use GIMP for Recoloring Textures (Because i'm a Rookie Game Dev) and Photoshop for the Sole reason to make Ace Attorney Styled Logo's (After i'm done on Paint.NET)
Ah! I see... Now my interest is peiqued quite a bit....I might try it out soon. Also...you're a rooke game dev? And I'm quite sure you can recolour textures in pixlr too....i only tried it once and it's exactly the same as the colour replace rool on photoshop. Also...b(r)owser only is good enough for me!