http://www.nikonchat.com/nikon-adapter-canon/

Should I get the Nikon D90 or Canon 550D?
Currently I have a Nikon D40 (and a few lens for it too) and wondered what it was that comes. I know you can not use Nikon lenses on a Canon without an adapter, so I was thinking of going for the D90 update (just to get better quality with my photos). I'm quite fond of and want to know what do you think (. Please and thank you for the answers:
The Nikon D90 is a camera semi professional and takes great pictures. Since they are already used to the Nikon system, I would recommend the Canon. T2i The Canon 550D or at the same time a great camera taking high-quality video, is actually an entry-level model. If the video is something interesting, then the Canon would be the choice. In my personal opinion most likely get better quality photos to invest in a high-end lens to switch cameras. A good objective Carl Zeiss, albeit expensive, to add more the pictures that you can imagine.
AF-Hilfslicht-Adapter Nikon-Objektiv – Canon EOS – by www.enjoyyourcamera.com