I now have the Extreme Tech Ti damper available from MotoWheels on my bike. Evidentally, it's the same as the ones that are sold under the Arrow name. It looks good and works well with good adjustabillity. It's light, and the mounting bracket makes fo a very sano installation (even if your front end in non-standard.
I used to have the damper that most people call the "Spareshack damper" which I think is made by Simpson. It does the trick, although the range of adjustment is very narrow (read: the adjuster doesn't do much). I've also seen them wear out and the damping becomes pretty minimal when that happens. Of course, you can buy 3 or so of these for the price of most of the other dampers available.
--Fillmore