Depending on your resolution (pixels), it will make a big difference on your pix as well as how many megapixels your camera is. I had a Nikon 2.0 and liked it, but upgraded to a HP 5.1 megapixel, and the difference is amazing.

You can try to make the pix smaller with a higher resolution (also more memory taken up that way). Sometimes it's just the settings, and you have to look in the manual and fiddle with the cam.

Your pics are great though.. I can't see anything grainy!