those are great pictures, especially for the pixel amounts. I ran the wheels off a sony mavica until it eventually just started corrupting every floppy I put into it. It took thousands of pictures tho
There's a great article by Ken Rockwell at:
http://www.kenrockwell.com/tech/notcamera.htm - about how pixel count really doesn't matter, we'd need 25megapixel cameras to even get close to film quality at 4x5 and 100+ mp to get close at 11x14 and larger sizes - the difference from 4-6mp or whatever isn't really enough to make a difference. Most of the pictures he has on there were taken with a 3mp camera, even award-winning ones. A lot of his medium format pictures are taken with a camera he bought for $3 or something
He has a lot of great articles on there if you are shopping for a camera:
http://www.kenrockwell.com/tech/buydigicam.htm or just wanting to learn how to take great pictures. Most everyone could learn a bit there and the articles read easy