I recently downloaded both the OSX and iPhone version of Stanza, with the intention of turning my iPhone into a good pdf reader. The verdict? Stanza on the iPhone is awesome for reading newspapers, books and magazines. Stanza is bad for reading tech documentation, especially those with diagrams and pics. I had hoped that Stanza might be good for tech docs, but alas my hopes were dashed. I still use it on an almost daily basis though, since there's a lot of classic books that are now in the public domain.