[muks]

Try cscope and xrefactory for emacs.

cscope is very good for searching through C codebases. You can use this with vim too. It has emacs integration using xcscope, and you can use sequences like C-c s g to quickly jump to a symbol.

xrefactory (though non-free) is very good with C++ navigation and can do refactoring. I have used IntelliSense with VAX and xrefactory is much better. This less known program is something incredible for C++.

[rhizome31]

Also worth mentioning Rope for Python refactoring. Rope's extract method works rather well in Vim.