Using heavy web frameworks like Django or Ruby on Rails leads to a bunch of boilerplate code in directory structure. Two vim plugins help out with some heavy lifting: Snippets and vtreeexplorer. The two of these add the essential features of textmate into vim, complex abbreviations and a hierarchical file browser.
One install note for Snippets v1.2.1, you not only have to create the ~/.vim/after directory, you also have to source the vimball from within vim (i.e. edit the vimball and then run 'source %').
As David notes below, NERD_tree works like vtreeexplorer. It seems a bit more stable than vtreeexplorer, in that its vertically split directory listing seems more stable than vtreeexplorer's (vtreeexplorer would reset to horizontal split on buffer close). Thanks!