Google cloud print is a cool tool that lets you print from any of your mobile devices, tablets, or computers to any of your printers, anywhere! It's awesome for me because if I get emailed a PDF I need to print, i can send it to my printer at the office with just one click.
To set-up google cloud print, you just need a computer running google chrome that's connected to a printer (e.g., my office computer that is networked to my office printer), or a cloud-ready printer. Click on the google chrome's settings button and go to "show advanced settings." Scroll to the bottom, and you can add printers to google cloud print. Then just download the app from the the android, or apple app store and you should be good to go!
You can also cloud-print to other devices! This is an easy way to zap PDFs over to your mobile or computer (although I prefer using dropbox)