Dell has released its lightest-ever business laptop for busy execs with weak arm muscles.

The 2.5lb Latitude X1 has been designed with business travelers in mind, from its reinforced casing that wards off shifting airline baggage to a sealed keyboard that limits the damage caused by coffee spills. Dell reduced the size of the power adapter and battery to get the weight down.

An optional six-cell battery available with the system will provide up to six hours of battery life. It ships with a three-cell battery. The base configuration costs $1,699 with a Pentium M Ultra Low Voltage, 256MB of DDR2 RAM, a 30GB hard drive, a CD-ROM, and Intel's 802.11b/g wireless chip. It has a 12.1-inch widescreen display.

Business customers can purchase the notebook with service plans that provide for next-day repairs within the US as well as international plans that cover travel elsewhere in the world, Dell said.

Ultraportable notebooks have remained a niche market in the US, despite their popularity in many other parts of the world. This has started to change in the last six months as Intel has introduced newer versions of the Centrino, bringing down the cost of older versions.

HP's lightest business notebook weighs in at 3.5 pounds, but comes with the regular version of Intel's Pentium M, which will outperform the Ultra Low Voltage version.