Airprint is a interesting protocol, that lets any iOS device connect to a printer to use it. Sadly, Mac OS X 10.6 does not contain an Airprint server so you cannot let your computer share the printer for the iOS device. If you have a Synology NAS, there is a way around this problem:

• Make sure you have a recent version of the Synology software (this works with DSM 3.1 – 1613)
• Connect the printer to the NAS using a USB cable
• Log into the web interface of the NAS
• Open the Control Panel
• Open the External Devices item, you printer should be present in the lower pane.
• Click on the USB Printer Manager menu
• Check the Enable Airprint item, and select the driver model matching yours the best. In my case I have a Brother HL-4040CN printer, but that model is not present in the list, but selecting the HL-5040 works fine.