A comparison of iPhone photo viewer / sync applications

I’m looking for the perfect iPhone application that will let me show my artistic and casual photography. My ideal qualifications:

– A great viewer / slideshow mode that supports autorotation, light zooming, an good overlay, etc
– A true sync (not a cache or a download) so I always have an “offline” copy of my photos
– Works with a good photo sharing service (picasaweb, flickr, etc)
– A solid UI that will act as a good showcase for my photos
– Intergrates with social media for both me and my guest viewers

To date, nothing like this exists, but I have started a preliminary google spreadsheet listing the apps currently on the market and how well they do.