A leak on Thursday suggests Apple may be producing a newer iPhone with at least cosmetic differences. A source for Mac Observer has snapped a photo of an iPhone with the model number A1303, which isn't believed to have appeared on existing iPhone 3G models; a 16GB iPhone 3G owned by Electronista, for example, carries the number A1241. The device also has a matte black finish instead of the glossy black used on the existing model, but also retains the FCC markings and other text which would be covered up in a treatment by ColorWare or other custom-paint firms.

Nothing else about the phone is mentioned in the leak, including whether or not the back still uses plastic or has switched to another material. The site cautions that, while its previous sources have been "reliable," the image has yet to be corroborated and may still be doctored.

Apple is known to occasionally introduce minor revisions of existing products with different model numbers, though a change in finish implies a more significant change. Both Apple and third parties have implied that a major revision is due in or near June and thus that any case leaks now are of early prototypes rather than imminent models.

Readers are encouraged to compare the model numbers for their iPhones to verify the accuracy of the report.