Increasing Ubuntu ISO size for USB drive-based install

I've seen this discussed on other forums, thought i would bring it in here.

USB drives are increasingly looking like a good method of installing the system either via LiveUSB or a persistent install.

With this in mind, why not release a 1gb/2gb iso/img along with the usual cd-based version? think of how much more could fit into the extra 300mb/1.3g!

Because then they would have to support yet another image, and they already are stretched between the many official images and such.