Nokia's latest clamshell phone for T-Mobile features interchangeable front and back Xpress-On covers with Nokia's "hidden until lit" translucent front cover that shows the time, date, music track info and a variety of patterns. Three colors are included in the box. The Nokia 7510's other hot feature is UMA calling, otherwise known as T-Mobile @Home service. With an @Home plan you can make unlimited domestic calls over WiFi without using plan minutes. The phone runs S40, has a 2 megapixel camera and a strong web browser.