I'm at Brooks Institute of Photography, and Macs are the choice computer and laptop for photography and digital imaging. The Nikon D100 can be found on the used market for approx. $600, or the new D70 are both excellent digital cameras. If you already own Nikkor lenses, they work with both the D100 and the D70. I own a D1X and the images are stunning. Check out my website for samples of images using the D1X. Canon also has excellent digital cameras.
http://homepage.mac.com/rosstamann/PhotoAlbum10.html
http://homepage.mac.com/rosstamann/PhotoAlbum10.html