The Nokia N91, a slider-style update to the wildly popular clamshell-style N90, is arguably one of the most advanced phones on the market. The Nokia N91 has a feature list a mile long. This high-end music smartphone sports a 4 GB hard drive, a music player, a 3.5mm headset jack for listening on your favorite headphones, a stereo FM radio, and dedicated music keys. Connectivity includes Wi-Fi, Bluetooth, and USB 2.0 with mass storage mode. Other features include a 2-megapixel camera, speakerphone, Flash player, and EDGE data.