Do you happen to know about printing to wireless printers, especially the Canon MX870, from an iPad?
I wouldn’t have chosen your question if I didn’t. That printer doesn’t natively support AirPrint, the feature introduced in iOS 4.2 that lets your wirelessly print to a small number of HP printers. Fortunately there are other means.
If you want to print just photos from your iPad, Canon offers its free Easy-PhotoPrint app. I don’t own the printer and haven’t used the app so can’t vouch for its effectiveness, but hey, it’s free. Give it a shot.
If you want to use the printer for more than photos—to print documents, for example—try Ecamm Network’s Printopia. As my colleague Dan Frakes states in his admirable review of this just-as-admirable utility, “It doesn’t matter how a printer is connected to your Mac—if your Mac can print to it, it works with Printopia.
I’ve used Printopia with other printers in my office and can vouch for its effectiveness and ease of use. Download the demo and see for yourself.