Android's Dream is one Scalzi that I've never read, although he cops often to the butt/fart aspect of it. I am surprised that you can't tell them apart as I think they each have a distinctive style, although maybe the Stross ones about the lovecraftian government agency do have that silly vibe.

I've been using Stanza for my ipod touch, and am thrilled at how just plain readable things are, although so far I have not paid for any content (which leaves me with a lot of stross, doctorow and rucker)