HP Cloudprint is a free online printing service that lets you print documents and spreadsheets from your cell phone anywhere in the world. As long as you have the document in your mobile phone, you can print a hard copy on any printer.
HP Cloudprint works like this – you save the document as PDF to HP servers via the internet. The system then assigns them a document code, and transmits that code to a cellphone, making it possible to retrieve and print the documents from any location.
Later, using the SMS message the service has sent to the user’s cellphone, it is possible to retrieve the documents by entering the user’s phone number and a document code on the Cloudprint Web site. The documents can then be retrieved as a PDF, ready to be printed at a nearby printer. Link.