If you don't mind crude ... reduce the resolution and reduce the frame rate. I sent an hours' worth of clips to someone through the 'net as 160x120 15fps Cinepak files. The total file size was only about 100MB and (if i recall correctly, but i may be forgetting) i think it only took me about 40 minutes on an 866MHz P3 to encode the whole lot.
Generally the more compression or the higher the quality setting, the longer it takes to render. It doesn't seem to matter a whole lot which format is used.
I chose cinepak because the extention was .avi. I had had the other person install the demo of Vegas so that she could play around with the initial edits with the small versions of the clips. After she got a rough cut together she sent me the .veg file and i was able to open it up with the full size DV versions of the files for the finishing and final rendering.