STSgirl has a post about the forefront of credit theft:

Could micropayments be the new way to validate stolen credit cards? tinyurl.com/ybsdowp

The full article details a theory- criminals could use micropayments to check if credit cards are valid.

Micropayments are very small transactions used for non-traditional items, like virtual goods or song plays. The theory goes that in the same way crooks used small gas transactions in the past to steal, they could use micropayments in the future.

The lesson for consumers is simple: watch your statement carefully for any suspicious charge, no matter how small. Even a penny could serve as a warning sign of a stolen card.