Lenovo today tossed its hat in the ultra-mobile PC (UMPC) ring today , with the introduction of the Ideapad S10.

The mini-Lenovo notebook features a 10-inch screen, and an 85-percent size keyboard. A nine-inch version will be available to users overseas. The Ideapad can way as little as 2.4-pounds, should you opt into the 3-cell battery, which should give you about three hours of use. The notebook also ships with a six-cell, which should give you double that.

The system ships with either an 80- or 160GB hard drive, both of which run at 5,400-RPM. It runs features a 1.6GHz Atom N270 processor with up to 2GB memory, Intel 945 GSE Express chipset, and GMA 950 graphics. The S10 boasts two USB ports, a Webcam, a 4-in-1 card reader, and an ExpresssCard slot.

The Windows XP edition comes in $399 and $449 configurations. A Linux version will be available overseas.