Harman Kardon is still relatively new to the GPS game, but it looks to be increasing its presence in a fairly big way today, introducing three new units in its "Guide + Play" series. Those include the low-end GPS-310 model (a follow-up to the GPS-300), the slightly more capable GPS-510, and the top-end GPS-810. Each of those pack a 4-inch widescreen display (or 4.3-inches on the GPS-810), along with text-to-speech functionality, 2GB of internal memory and, of course, all the usual GPS and PMP features you'd expect from a device dubbed "Guide + Play." The GPS-510 ups things a bit with real-time traffic info, additional video options, and support for SDHC cards, while the GPS 810 tops things off with a wireless rotary controller (seen above), an FM transmitter, and built-in Bluetooth for hands-free calling. Look for the whole lot to be available next month, with the GPS-310, 510 and 810 setting you back $350, $450, and $600, respectively.