The Firefly, which is available through Cingular, is a mini-cell phone for the 8-12 set. It has dedicated Mom and Dad button (What if Dad wears mumus or kilts and Mom wears pants? What if it's two mommies or two daddies? Wow. The unexpected gender politics of key caps.) and has a 911 button for emergencies. General usage is uber-simple—press and call. The review found some quirkiness with the initial set-up, but one can only assume that once the Mother-Unit and Father-Unit numbers are programmed in, all the Child-Unit has to do is press a button.
The phone uses prepaid cards to charge usage and supports 850 and 1900Mhz GSM and offers about 6 hours of talk time. It's quite small and rounded, making it a perfect "I-lost-it-in-the-river" item for the youngster in your life.
Review of the Firefly mobile phone for kids [MobileBurn]
Update: Sascha Segan wants you to know he reviewed this phone in March.
Firefly Phone Review [PCMag]