Still unpacking boxes and getting settled in here at Posterous. I just downloaded their iOS app and noticed a pretty startling UX faux pas. The buttons for "View Post" and "Delete Post" have no visual differentiation (like, say using red for the delete action) and are separated by a single pixel. If they were aligned that closely side by side it wouldn't be as bad because the target area for your finger would be much larger, but as it stands now, you have to be pretty darn accurate.
(I'm assuming they display a confirmation dialog before deleting your post, but I didn't try it. Either way, the point stands.)