Xbox 360 Bluetooth Headset
Microsoft did a great job with the wireless controllers for the Xbox 360. The grips are comfortable, the buttons are placed well, but they still require a wired connection for the headset. Industrious Flickr user fateit77 hacked together a solution using Jabra's A210 adapter coupled with the Jabra 250 headset, giving him wireless trash talking for all online gaming. The Jabra headset doesn't support Xbox 360 muting and volume control, so you need to do some manual hacking to set things up, but the solution is certainly a stopgap until Microsoft or a third party vendor comes up with an alternative solution. This is a bit pricy off the shelf, but if you happen to have the gear laying around, you can easily game wire free.
Jabra A210
Jabra 250
