The Reiki Cafe 

Vinny has some mudras on his site (in the karuna ki section I think)

www.angelreiki.nu/

a good book on hand mudras is

Mudras Yoga in Your Hands by Gertrud Hirschi

Both James (www.geocities.com/fascin8or/index.html) and Vinny have information on exercises and meditations which are part of the Usui system

Also one of Frank Petter's books (I can't remember which one but think it is Usui's handbook) has information on a hand mudra to 'collect' energy.

Walk in beauty,
Rebecca