Excelvan FM Transmitter + Car Charger + Remote Control Compatible with iPhone 4S/4/3GS/3G iPOD
I have the iPhone 4S.  The car charger will not work on my phone so that part is useless.  If you have an otter box then forget this being able to plug in…it doesn't reach far enough in.  Im accident prone so I like keeping the otter box on, but when its off and I have this thing plugged in, it does work well and the remote is handy.