There's a prefs file floating around somewhere. I don't care for it, because it doesn't actually shuttle, it only jogs at high rates (rather than playing at 2X, it jumps ahead in batches of frames).
This is a script/pref combo that I put together for VT it works for VT but I use a different prefs set for shuttle speeds than this one, that I've found to be smoother. If I get a chance on the weekend I'll find it and upload it. http://corin.com/vt_tutorials/shuttlepro/index.shtml