My fiance and I did this a while back -- bought a groupon/living social deal for discount online purchase of canvas wrapped photo. Since we have the digital versions of our engagement photos, we'll just make our own canvas print instead of paying the photographer an arm and a leg for it.
http://www.livingsocial.com/deals/300486?ref=iphone-conf-jp&rui=12105312This isn't the same website that our deal is for, but worth thinking about!