Currently Being ModeratedDec 7, 2011 1:17 PM (in response to \"Mo\")
rbii's post is great, and you will see the HP Photosmart 7510 series listed as an AirPrint capable printer.
As for your HP Photosmart C6280, you can download the HP ePrint Home and Biz app from the Apple App Store. The app will allow you to print from inside the app, photos, documents, a web browser, etc., to your Photosmart C6280 over a wireless network connection.
*I work for HP*