Seems like the illegitimate daughter of iphone 3 and 4. (my gadgets are all females)
Thinner, touch sensitive home button. But if you look at the very bottom, there are no speaker/microphone holes. Could it be the iphone nano? thinner, but not smaller per-se.
That image was making the rounds 2 years ago prior to the 3GS's release. Still looks sweet! And yep, there were already hopes of a bigger screen then too!