@Jonathan:
We do the exact same thing! I've never met anyone before who does that.

My goal is to have my expenses totally mapped out for a month and a half ahead at all times, which is why I alternate between two credit cards (one gives cash back, the other gives airline miles), with evenly spaced payment dates. I have a checking account, which holds only enough to cover the next bill, and a ING savings account, where I put the rest of my money. I always pay my credit card bills in full, and so I get a free month-long loan with bonus cash or miles. Using a credit card for all my expenses means that I can look ahead, make a note to retain the amount from the paycheck immediately before the bill is due, then save everything else. With a debit card I wouldn't have that luxury.

Maybe it's mainly a psychological benefit, but I'm very satisfied with this approach.