Everything USB posted an in-depth review on Logitech Anywhere MX Wireless Mouse.

No stranger to the ubiquitous pointing device, Logitech boasts an impressive 20+ year history building mice and computer peripherals. Having surpassed the one billion mouse mark back in 2008, they are the undisputed leader in electronic rodent computer peripherals. New for 2009, the Logitech Anywhere MX wireless mouse combines wireless connectivity with unique "Darkfield" tracking technology for a mouse that is said to be able to track on pure glass and other highly reflective surfaces. Designed to be a fully-featured portable workhorse, the Anywhere MX also brings a rather unique scroll wheel to the party. How well does it all work in the cold, cruel world? Come to our glossy new labs to see if the Anywhere MX can track straight and true.

Logitech Anywhere MX Wireless Mouse Review