The Postal Service authorized online purchase of postage today, which was pretty much expected since they’ve been working on it for more than a year.
However, some of the reports I’ve read say they authorized four providers, while others say two. If it’s four, I have no idea who the last two are, but the first two are easy: E-stamp and Stamps.com.
Addendum: It is only the two providers who have been authorized. And the postage uses the two-dimensional barcode (like UPS uses) to store the information. It looks like this: