The 6215i is the first cellphone in the US with an OLED display. Why is that important? Because it's the tip of the OLED spear, a display technology which may just replace LCDs in cellphones sometime within the next few years. This phone has two displays, one 128x128 and one 96x64, that are both OLED. These screens are lighter and cheaper to make, which makes both consumers and manufacturers happy.
Other features: VGA camera, speakerphone and voice dialing. Nothing very special, other than the OLED. You can pick one up for $50 with a two-year soul agreement from Verizon.