Currently Being ModeratedMay 10, 2011 4:26 AM (in response to Imannym)
You need a compatible AirPrint wireless printer which will set itself up automagically. Otherwise if you have a Mac running 10.6 or later there is an application called AirPrint Activator which will allow you to share any printer connected to a Mac on your wireless network.
Here is the link for the download with a very easy to follow setup guide and video.
This is an option for Windows 7 but I haven't used it myself so I don't know how useful it is: