toggle.el

I just released toggle.el, allowing you to quickly open corresponding files via a dynamic mapping.

From the description:

This package provides the ability to quickly open a corresponding file for the current buffer by using a bi-directional mapping of regular expression pairs. You can select a mapping style from toggle-mapping-styles using the toggle-style function or set your default style via the toggle-mapping-style variable.

There are 3 different mapping styles in this version: zentest, rails, and ruby. Feel free to submit more and I'll incorporate them.

Example Mapping (ruby style):

blah.rb <-> test_blah.rb
lib/blah.rb <-> test/test_blah.rb

Get it (and other packages I'll release soon) via: http://www.emacswiki.org/cgi-bin/wiki/RyanDavis