Best answer as chosen by user Coryphaeus: Don't think you can do that but,

by mrmacfixit Moderator - 1/8/13 3:54 PM

In Reply to: How do I or can I . . . by Coryphaeus

why is resizing such a problem?

When you email a photo from the iPhone, don't you get the choice of sizes?

Just one click will resize the photo. Tested from 1.7Mb through 516KB, 101KB to 37.3KB

Doesn't the 3GS have that function? My original iPhone did.