I do not have an Airprint-ready printer at home. But with the help of a little free tool I managed to configure my Canon MG8150 as a device which will be recognized by both iPhone and iPad.
Just download the AirPrint activator for Windows and run it one time. You need to make sure to use “Run as administrator” as a service needs to be installed.
If you have activated the local Windows firewall you need to add a rule to allow incoming traffic for “c:\airprint\airprint.exe”. Although it was not described in the help I needed also to add a rule to allow incoming UDP traffic on port 5353.
Now you can just select “Print” in iOS and your shared Windows printer will available for selection. Just enter your Windows user / password one time and you are able to print from your iOS devices.
[Update 02.03.2012]
As the above software is no longer working for me and I did not find out the reason, I have changed to “Fingerprint” now. It does cost a little bit but it is working like a charm even with iOS 5.1.