My camera is a Nikon D40, I LOVE it. It doesn't do tank shots well, but maybe that is because both of our tanks are curved?
My macro setting isn't all that great for the tanks, and I can't afford a macro lens (Even more so now that I need a new laptop) so I usually end up cropping the picture to get more of a zoom. The poor mans macro.
Duncans...oohhh duncans. When I saw how expensive they were, I thought they were sooo over rated, but I got them for a good price, and now they are my favorite thing in the tank! The babies are having babies though, and I have no idea what I am going to do.