(copied this from my post on VJCentral, before these forums were up)
Figured this one out - used it live for the first time last night - very handy.
If you've got a Griffin Powermate ($45), install the software, and then go into System Preferences -> Powermate.
Add a "New Setting..." and choose Grid from the Application pop-up.
Set Rotate Right -> Cursor Down.
Set Rotate Left -> Cursor Up.
Set Short Click -> Send Key 'K'
Set Long Click -> Send Key 'J'
Now when you're playing your clips in Grid, you can press the powermate down to activate Mouse Speed (K), and your powermate will now control the speed of the clip! Very useful for fine adjustments, switching between forward and reverse.
If you want your clip to go back to normal speed, click the powermate once, and then click and hold it down, this will send a (K) to turn off mouse speed and then a (J) which resets speed to 1x.
Surya
Los Angeles Video Artists
http://www.la-va.org