Several companies offer biometric keyless locks for entry doors, mostly in the $200 range (as of 2008). One company is Kwikset. Its SmartScan locks are available at home centers and hardware stores (find retailers and more info at Kwikset.com). When you swipe your finger across a sensor, it reads your fingerprint and activates the battery-powered dead bolt. You don't need a key or a key code. Installation doesn't require hardwiring, and the batteries last about one year.
Other companies also sell keyless fingerprint locks. Search online for “fingerprint door locks.”