A typical image being uploaded is going to be about 2.5 MB from a 4 MP camera. Ideally, I would like the full size image to be resized to 150K - 250K upon being uploaded or constrained to about 575 PX either way. I can't seem to make this happen in the configuration settings in the admin area.
It's available in the next version of Coppermine, 1.4. I think xp publisher can do this too.
or you could have a look at the mods&hacks board