My laptop uses a fingerprint swipe login. Usually works well but occasionally I've had just a terrible time getting it to recognize my index fingerprint and have to <gasp> manually login.
Today I realized why. After typing on my BlackBerry for 30 minutes, my fingerprints are distorted from holding the Curve and the bio-authentication thingy can't recognize me! :-)
Posted from my CrackBerry at wapforums.crackberry.com