This has probably been pondered, but something occurred to me whilst entering my new home.. The guard house grants access based on your fingerprint. The system works pretty sweetly..
Now.. because i have about a zillion accounts, i kinda group my passwords.. since i know services admins on most irc networks read your password, i use XXX for low level access (this might include try once trial software logins).
Slightly more reliable software logins (vmware page / ms partner page) i will use YYY.. i think most people do this..