I've been meaning to post about this gizmo since the Flytying Symposium back in November, but had lost the website of the parent company.
We came across a booth that featured a device to make dubbing brushes called "the Twister". It requires no electricity, batteries, etc., and the tension can be easily controlled by the user. It was listed at the show for $70, but now at the website the starter kit is listed at just under $90. I'll probably eventually get one because of the amount of dubbing loops and brushes that I use on larger flies.
By the way, my wife has been tying flies for about a year, and while she is by no means a pure beginner, she gave the Twister a try at the booth and then tied her own wooly bugger with the brush in about 10 minutes. She may want it more than I do....
You can check out the company at www.justflytying.com.