RoboPrint is being billed as the first Windows Phone 7 application to let you print to any printer, anywhere, at anytime.
And it's not restricted to just one printer. Roboprint allows you to have multiple printer profiles for your home printer, your office printer, your friends printer, or your secretaries printer. As long as it is reachable on the internet Roboprint will access it.
RoboPrint provides you with a free Windows host application (available at Roboprint's website) that you install on a computer attached to your printer (either directly or via a share), and from that Host RoboPrint will connect to the Windows Phone 7 application and printing can begin. You can install the host program on as many computers as you want.
Roboprint is limited on the content you can print though. You can print emails, web pages or photos. It's a free application and you can download it here (opens Zune) at the Marketplace.
Update: Just heard back from the Developer. The app was pulled temporarily to fix a bug. Blue Planet states Roboprint should return to the Marketplace very shortly.