different keypad design. They use retro 1980s styling twists and a geometric diamond pattern on the surface. The Nokia 7900 Prism and Nokia 7500 Prism are two new style-statement mobiles from Nokia.Nokia 7900 Prism
Opposite its sleek, liquorice-black front, the Nokia 7900 Prism comes with an anodized aluminium backcover, which is coin-stamped and laser-etched in Nokia Prism's signature diamond-cut design. Its design is amongst the first to feature an Organic LED main display that supports up to 16 million colors and displays light-focused screensaver graphics. In addition, the Nokia 7900 Prism features a "living wallpaper", which subtly changes throughout the day according to time as well as battery and signal strength, so that each screen is unique.
Nokia 7500 Prism
The Nokia 7500 Prism is the Nokia 7900 Prism's quirky sibling. The Nokia 7500 Prism's slick black exterior is spliced with bright, interchangeable color accents. The Nokia 7500 Prism has a 2 Mpx camera and it can record high quality movies. The Nokia 7500 Prism can play music for nine hours and hold up to 1500 songs on an optional 2 GB microSD card.
Here is the Nokia 7500 Prism commercial video (Chinese version)
More details available here