+1.... I even use my belkin tunesync dock to sync and charge without issues.I have used my iPod charger with no problems.
There may be some truth behind using iPhone Specific products with the iPhone. Yes, it all should charge the iPhone, but I bought the Xtrememac car charger and it completely wiped out my radio. Like, literally as I unplugged the charger without even having the usb cable connected, the radio came back on, but as soon as I plugged it back in, complete static!
The Griffin gets the job done perfect though!