HP has put out a firmware update for 8 models of LaserJet printers, adding support for iOS's AirPrint feature for iPhone, iPod touch, and iPad. The newly empowered models are:
Previously supported models:
If you have one of those models, get on over to HP's support site and download your update. If you're considering a new, AirPrint supported printer, you can add those above to the 5 previously supported models, for a grand total of 13 to choose from.
Now we're just waiting on Apple to fix up that AirPrint to networked printers feature that didn't make it into iOS 4.2 or 4.3 but we'd really like to see in iOS 5!