Lenovo Lenovo. ThinkPads (a brand acquired with the purchase of IBM's personal computing division in 2005) are built with a protective roll cage that includes a magnesium alloy frame and shock-mounted hard drive, making an "air bag" for the PC. Lenovo says the 4.23-pound ThinkPad X60 tablet PC has a keyboard that swivels under the screen so you can take notes and draw sketches without the keys getting in the way. 866.426.1316. www.lenovo.com.

Motion Computing Motion Computing. The 4.3-pound LE 1700wt tablet PC allows you to seamlessly switch from touchscreen to pen mode, so you can write a memo with the digitizer pen and then touch the screen to navigate to another application without interruption. Motion says the unit's Intel Core 2 Duo processor makes it fast without draining battery life; its battery lasts for a full day of work in the field without recharging. 866.682.2538. www.motioncomputing.com.

General Dynamics General Dynamics. Long-time defense contractor General Dynamics touts its Itronix GoBook XR-1 as military grade, but it also can handle the hazards of a jobsite. With its IP54 sealing for dust and water intrusion, plus fully sealed input/output ports, the GoBook XR-1 can take mud in the face, and the hosing your yard boss might use to clean it off. It weighs 6.8 pounds. 800.441.1309. www.gd-computing.com.

Panasonic Panasonic. The Toughbook 19 converts to a tablet PC with a swivel of its screen. Its shock-mounted hard drive is surrounded by a protective polymer compound and boasts full magnesium alloy construction. The 19 has BlueTooth and GPS capability and comes wireless-ready for Sprint and Verizon Wireless networks, Panasonic says. It weighs 5 pounds. 800.662.3537. www.panasonic.com/toughbook.

Xplore Technologies Xplore Technologies. The iX104C3 rugged tablet PC boasts an Intel Pentium M 753 processor, allowing users to run a full Windows operating system on a tablet and integrate with apps back in the office. The company says its triple-layer magnesium construction stands up to dust, moisture, and even a drop onto concrete. The iX104C3 weighs 4.95 pounds. 888.449.7567. www.xploretech.com.