Keep in mind, the F3 doesn't work with CDMA networks (like Verizon). There theoretically is an F3c that does work with CDMA networks, but I've been looking for it for weeks, and haven't had any luck. If you find a source for the F3c, please let me know.
From the phone's "features": "This unlocked cell phone is compatible with GSM carriers like AT&T and T-Mobile. Not all carrier features may be supported. It will not work with CDMA carriers like Verizon Wireless, Alltel and Sprint."