I'm not going to knock the Facetime suggestion. If it is truely an "Open" standard as Apple suggests, someone should implement it in Qt then people won't need to buy iPhones or Macs to use it. Nokia would be reluctant to use anything Apple has come up with due to their ongoing patent case though so it would have to be a 3rd party.

Here's my list of photography apps for iPhone. I love Classic Print on the N900 but these apps have better features and have also nailed the UI.

Andigraf
Polarize
Pictone
TiltShiftGen
CAMERAtan