Here are many dongles that are compatible with the NXT that may not be on LEGO's website.
Here are some ones people find compatible (All links in this list opens a new window):
Kensington Bluetooth USB Adapter 2.0 (Model:K33348). I use this one and I find it easy to use except for one time. It is handy and nice for downloading programs without the USB cord and I would recommend it to anyone.
Level One - MDU-0025USB Bluetooth 2.0 It has been tested with MATLAB toolbox and has been given a great rating for compatibility. This class one product has been tested with Windows and Linux. This dongle may have poorer or better experiece because it has only been tested with MATLAB and not NXT-G.
AVM - BlueFRITZ! USB v2.0 (German) It also has been tested with MATLAB tool box and has a 3/3 rating. The recomender says: "I can totally recommend the AVM Blue!Fritz Bluetooth dongle. It has its own very easy-to-use software, a lot of features, and showed the fewest problems with uninstallation or multi-user platforms (with restricted user accounts). On the negative side, it's the most expensive." This dongle may have poorer or better experiece because it has only been tested with MATLAB and not NXT-G.
NOTE: I am not held responsible if any of these dongles don't work with the NXT. Though they should.
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