A: 

Vim is a pretty amazing editor, and has many of the benefits of an IDE. I'm sure you could figure out how to do this, even if it's never been done. However... to me it seems you're crossing a line. Why not use use one of the full blown GUI IDEs out there like XCode, Eclipse or Visual Studio if that's what you want? If you're addicted to vi key bindings you can probably get a plug-in to do that for one of those.

dwc
+6  A: 

vimscripts has a plugin called autocomplpop.vim that does what you want.

Bryan Alves
Awesome. This plugin totally rocks. Thanks.
Nate Murray