ace_at_mind's Semi-DIY: 12VDC Socket Install. With the fuse and everythinng, it's pretty much the same thing as making your own without buying the part above except that you will have a waterproof 12v DC auto socket for other things and you can be more selective about iPhone charging.
When I did it I figured that the "Made for iPod"/"Works with iPhone" products would be more likely to include a real VRM as opposed to just stepping down from 12v. I also knew that the wall plug outputs 1A/1000mA instead of the typical USB standard of 0.5A/500mA, so I specifically hunted for one with a "FastCharge" or "QuickCharge" port. I found the Belkin Charge Duo at Wal-Mart, The Apple Store, and Frys (can no longer find it at Wal-Mart). It has two USB ports, one is 1A and the other is 0.5A. It includes mini USB, iPod/iPhone USB charge/sync cable, and is MFI/WWI-certified. The ideal mount point is in the semi-DIY.
