T-Mobile announced yesterday the availability of the new Samsung Katalyst (t739), a slider phone featuring built-in WiFi with support for T-Mob's HotSpot @Home UMA calling service.  Katalyst is the third HotSpot @Home handset from the carrier, and slots in between the entry-level Nokia 6806 and the high-end BlackBerry Curve 8320 smartphone. 

Katalyst is being introduced at a price of $79.99 with a two-year contract, and features a 1.3 MP camera, Stereo Bluetooth support, and a microSD card slot.  There's no 3G and the specs are pretty old hat at this point, but if you're into the whole Wi-Fi calling thing and don't need a smartphone, it's a much nicer option than that Nokia.