There are lots of things you can do to better organize your vim configuration, starting with using pathogen.
Apart from using pathogen, what I like to do is having small snippets of configuration on separate files to tweak specific things. Here's my .vimrc:
" Setup for pathogen.
call pathogen#runtime_append_all_bundles()
call pathogen#helptags()
" Load additional plugin configurations and stuff
for rc in split(globpath(&rtp, "rc/*"), "\n")
execute "source" rc
endfor
First part is the setup for pathogen. The second part is what I'm talking about, I go through every file in my .vim/rc directory and load every snippet of that folder.
A fun thing to try is to make every snippet "self contained". That way, if someone browsing your config thinks the thing you are setting up there is cool, all he has to do is copy that single file to get the specific piece of functionality.
BTW, since I use gvim most of the time, on the .gvimrc I just source the .vimrc, plus a few GUI tweaks (removing toolbars, menus, etc).
source ~/.vim/vimrc
" ... some gui settings.