Brad Williams pointed this out on Twitter, and I haven’t seen it before: WordPress.com has a page that allows users to inquire about a charge they didn’t recognize. You type in your name, last four digits of your card, the date and amount of the charge, and it helps you find what it’s from. It’s a pretty slick feature, and a good one for for WordPress.com especially, considering you may have a single account hooked up to dozens of websites.