My credit card left home without me. Now what?

I try to never use credit cards to buy something that will be gone before the bill comes. It's a quirk, I know, but it probably spared me an awkward moment at the gas pump.

Citi apparently shut down a lot of its gasoline company credit cards without warning. That could be a nasty surprise if you just filled up as gas prices kiss $2.50 again. Leaving you with suddenlly worthless plastic is just one of many things card companies are doing before some new consumer friendlier regulations kick in, says Bill Hardekopf of Lowcard.com. And what is frustrating is that shutting off your credit unilaterally is neither illegal nor even among the worst things card companies can do before the new regulations take effect, consumer advocates say.

But what do you do if you've just pumped $30 in the tank, the only cash you have with you is small change in the ashtray, and your credit card is declined? Most immediately, if you don't have a second card to fall back on, talk to whoever is watching the gas pumps inside, have some photo i.d. ready that might convince them you aren't a deadbeat, and arrange to pay the $30 as soon as you can.

Next step, start some damage control. Cancelled credit cards will change your credit score, even if you didn't do anything to trigger the cancellation. Contributor W. Allen Morris to AssociatedContent.com outlines some of the math you will need to do and some of the ways you can use existing cards to patch any damage. Jim Wang over at Bargaineering.com offers some additional tips, though I'm personally more uncomfortable with debit cards than he seems.

And think about paying cash for your next fill up too. In addition to heading off credit card hassles, paying cash for everyday expenses is great way to control spending too.