I know I've looked for one in the past, but if you have need of one you can get info about it at Miguel De Icaza's blog (I still read it even after our little tiff - imaginary). Even better it is under the X11 license, so you can do pretty much anything with it (apart from claim it as your own).

Apparently it came about from the Summer of Code, so we can thank the Mono guys and Google. I am now awaiting a flood of .Net BT clients Smiley