Epson, the printer colossus, has released an iPhone app that allows photo printing via a Wi-Fi connection. Epson iPrint (iTunes link)
You have a few limited print options: in addition to standard printing on plain paper, you can produce borderless prints on fancy photo paper or choose from a number of paper sizes (4-by-6, 5-by-7, letter size, and A4). Of course, if you're printing photos taken with the iPhone camera (even the one on the 3G S), be prepared for mediocre quality--iPhone pictures really aren't meant to be framed.
Epson is the third to join the iPhone printing game. Hewlett-Packard released its own app--oddly enough, called HP iPrint Photo--at the beginning of 2009 and updated it in November and Canon also released its Canon Easy-PhotoPrint for iPhone this fall.
Epson's app works on any iPhone or iPod Touch running iPhone OS 2.2.1 or later and is available for free in Apple's App Store.
This story, "Epson Releases IPhone Printing App" was originally published by Macworld.