I'm working on a project now that is insalling computers that use a fingerprint reader for user login. It's pretty simple stuff at this point, and works pretty well. (I can't for the life of me remember who makes the software we are using)... Some people's fingers don't work well with it, though. If you worked on a farm at some point, or worked with a lot of hard cleaning chemicals there's a good chance it won't recognize your print.
I have read some articles that some grocery store chain down south is installing fingerprint readers at the checkout and you can pay for your groceries by registering you print and checking account with the store and then just pressing your finger to the reader. That's it, no paper, no signitures, no cards. Just finger on, here's your reciept.
I like it. Some privacy advocates don't like it, but I for one am more paranoid about giving out my SSN. If someone wants your print they could get it from the keyboard you type your password/pin in. You can't lose your finger print, or have it stolen (without knowing it's missing right away). These devices are already pretty good at ignoring 'fakes', and I've seen some that have hea sensors to make sure the 'finger' being read is warm enough to be a persons.
Anyways, in my experience with them they are alright. I would like to have one at home that I could use for my passwords at websites and such. Have my password be a random series of characters and have the reader insert it only after verifying my finger. Would work nice. Same for the ATM... no mor lost cards or trying to keep the guy behind me from seeing my PIN...