I haven't used those self-check out machines at grocery store lineups --yet. I guess I have to use my credit card? 'Cause my personal rule of thumb is never use credit card for my groceries. It forces me to pay cheaper basics in life, ie. food , by cash. It forces me to budget properly by experiencing the disappearance of money immediately when I buy basics.

And no, I don't use debit at all. Not safe.

Yea, have been using the airport check-in machines for past ...8 yrs. I've taken a number of trips 'cause Canada is a huge country. Very convenient those airport machines.
http://cyclewriteblog.wordpress.com/ (How cycling leads to other types of adventures, thoughts)