Ok... This Buy.com deal is now live as well...

Snag the Xbox 360 Wireless headset for a low $38.59 (35% off) w/ free shipping this week at Buy.com!

Check it out:  Buy.com Xbox 360 Wireless Headset

Alternatively, Amazon has the headset on sale as well ($39.97)

Check it out:  Amazon - Xbox 360 Wireless Headset

Features

Experience enhanced clarity and performance without wires to tie you down. Embrace the stylish, ergonomic design that fits comfortably on either ear, with two sizes of removable ear grips for a perfectly snug fit. The headset utilizes the same 2.4 GHz radio technology employed by the award-winning Xbox 360 Wireless Controller for clear communications within a range of up to 30 feet. Take command of the situation and communicate with superior audio quality over Xbox LIVE. Up to eight hours of battery life per charge, with an AC wall adapter for quick, convenient recharging. Outfit your teammates (or rivals) with up to four Wireless Controllers and Wireless Headsets simultaneously per Xbox 360 console. Supports Voice Command for select games. Conveniently located Power On/Off, Volume, and Mute Controls are right where you need them. Integrated 2.4GHz wireless technology with 30'' range Communicate with others over Xbox LIVE Up to 8 hours of battery life per charge, with an AC wall adapter for quick, convenient recharging Wireless freedom with enhanced clarity and performance