Fliq is a free utility that allows two people over a Wifi connection to "fliq" photos (and contact information) to each other. It's a reasonably good idea, but the implementation is far from perfect.
The biggest problem is there is typically a 30-60 second delay between the time you "fliq" a photo, and the time your friend receives it. During this delay, there is no indication that the "fliqing has been successful. If either of you leave the app, the "fliq" will fail.
More to the point, Fliq doesn't really solve a real problem. If I want to share a photo on iPhone, I can quickly email it to any of my contacts. This is faster and more foolproof than "flicking" it. I could see a use for this type of file sharing for audio files, but not individual pictures