It won't hurt you to buy a 5 or 7 mp camera. The smaller formats are getting harder to find. Memory costs have come down.

A 3 mp image can be 500kb to 1.5mb. Depends on a whole bunch of variables, but lets say they average 1 megabyte each. Your minimal 128mb card will hold about 250 pictures.

You go to a 5 mp camera and your 512 mb card will hold around 330 pictures. I have an old one from a couple of previous cameras a 64 mb card holds 42 5.2 mb pictures in best mode.

Always shoot in the "Best" mode! You can reduce, crop and edit later. You can't make a "good" picture better, because the data just isn't there.

Optical zooms are the same as cropping out the edges of a picture. Picture quality only goes down.

About that saving as a TIF or BMP format, which do not compress the image, so you can edit and re-edit, without loss like compressed JPGs may produce. A 1 megabyte JPG file is a 15 MB BMP or TIF file.

Just figure they are 15 times larger than the original from the camera.

In other words 45 pictures, that can fit on your memory card, with space left over, will fill an entire CD if saved in TIF or BMP format!

The same CD will hold 700 JPG images.