Handyscope : iPhone Dermoscope
It seems that more interesting medical applications for the iPhone are being born. I was actually thinking of getting a dermoscope and it's actually a great idea to be able to convert your iPhone into one.
At the same time you can take a picture of the magnified image of the skin lesion for the records or consultation with a dermatologist. The price is still a bit high but not much more than a high end dermascope.