I've been using a Scottoiler Cramp Buster for a while a while now I find it makes a big difference, no more pins and needles in my right hand / wrist and its easy to move from bike to bike
http://www.youtube.com/watch?v=_Uyo5NxbMW0
http://www.youtube.com/watch?v=_Uyo5NxbMW0