Newly announced/released for the Xbox 360 from Play Asia:

With no cords to tie you down, the Xbox 360 Wireless N Networking Adapter is your connection to the fun of Xbox LIVE. Quickly download or stream HD movies, TV episodes, game demos, game add-ons, and more. The dual band adapter offers fast speed and great range* and contains an extension cable for off-board placement.

Price: US$ 74.40 / Usually ships within 5-15 days