Cxxcomplete is a project mainly written in Vim Script, it's free.
Tries to implement code completion.
This is a mirror of http://www.vim.org/scripts/script.php?script_id=1347
First, you'll need ruby support compiled in vim, and ruby bindings for gtk( ruby-gnome).
What it can do? Scans your tags file, and pops up a list of possible completions. The completions refers to your variables, and member functions/variables. http://photos1.blogger.com/blogger/4648/1229/1600/screen11.jpg
The script that scans the tags file is based on cppcomplete.