Printing from your iPad or iPhone

This application runs on a mac computer and will allow any networked printer to be used from an iPad or iPhone. It's a great deal for $20! We use it at my school and you can select what networked printers you want to use to print from iOS devices. You just need to run the application from a computer that is always on.
It's called Printopia and here is the website.
I highly recommend it if you are wanting to print from an iOS device without purchasing a new printer.