http://www.nintendo.com/consumer/wii_safety.jsp
the best line from that site?
QUOTE
For example, in Wii Sports bowling, the proper way to let go of the ball while bowling is to release the "B" button on the Wii Remote—DO NOT LET GO OF THE Wii REMOTE ITSELF. If you are having so much fun that you start perspiring, take a moment to dry your hands.
great stuff