Cortado Workplace is a free app that let you print from your smartphone.

Blackberry and iPhone owners now have the possibilities to print files right from their devices by using a free app called Cortado Workplace from a company named Thin Print AG.
Imagine being on the road with your smartphone as the only device with you and be able to print e-mails, computer files, photos or documents from your phone and onto a networked printer. All that is possible after you download the free app; from there, you will be using the company's cloud server to store for free files up to 1 gigabyte with a maximum of 3 megabytes per file, according to the New York Times.

For more, see NYTimes.com