In the ThinkPad X61, Lenovo has introduced its successor to the ThinkPad X60. The X61 uses Intel's Santa Rosa mobile processor. Otherwise, it's the same light, sophisticated ultraportable as the earlier model; like the X60, it lacks an integrated optical drive but offers dazzling battery life.

This 3.6-pound X-series member goes to the top of our list of ultraportables for mobile professionals. Our X61 test unit, with a 2-GHz Core 2 Duo T7300 processor and 2GB of DDR2-667 SDRAM, earned a WorldBench 6 Beta 2 score of 75, which is tops among currently tested ultraportables. The extended-life four-cell battery lasted an amazing 6 hours and 14 minutes.

The bright, 12.1-inch screen and the keyboard might feel a bit close at first, but the cramped feeling quickly goes away. The keyboard has no touchpad, but the eraserhead pointing device is first-rate and easy to acclimate to. The usual nice touches found on Lenovo keyboards, such as volume buttons and a one-press launch of the recovery system, are also present.

The UltraBase docking station adds four more USB ports (for a total of seven) as well as legacy parallel and serial ports. In addition, the modular optical drive has a side release, so you can swap with one hand between an optical drive, a second battery, or a second hard drive (those are optional accessories). Including the base, which is easy to snap on and off, the unit's total weight is a little over 6 pounds.

Our review unit, which included an UltraBase docking station with a dual-layer DVD burner, costs $1724 (as of July 27, 2007). The great performance and features, and its reasonable price, make the X61 our current top choice of ultraportable.

Carla Thornton