I thought I was the only one! 
I have to think which is going to give me the best rewards... and what are the statement dates so I don't end up with a balance posting that I don't want. (That has happened because I was so close to the stmt date when I used the card.) I try not to use a card within a week of the statement date, except for the ones that I let a bal report, which are Navy and my 2 Amex. Usually I end up just using my Navy because I feel badly having the cashier wait with their hand out and sometimes there are people in line behind me.
It's kind of ironic because 2 yrs ago, I had ZERO credit cards, so there was no choice. It was my debit card, and that's it.
I recently had this problem when buying gas, and then later that day when shopping for a pair of new sneakers. My problem though, is that I now carry around my PRG Amex, my Discover More card, my Chase Southwest and then like 2 of my NFCU cards, plus my debit. Sadly enough, it got so frustrating sitting at the pump that I just swiped my debit card instead. 
A couple of posts ago, someone said something that made total sense to me. They carry 2 cards around at any given time. I think I will do that now.
And to think, I was just online yesterday looking for a new wallet to hold all of the plastic. I don't need that kind of headache. I don't exactly want to look like a card junkie either in front of co-workers and friends....
Starting Score: 686 TU / 683 EQ 01/17/2013