this is a quick patch primarily aiming at making lighting/setting up reflections a bit easier. In addition to the existing "snap align to surface normal" it indroduces a new option "snap align to reflection". This enables the user to just point at a position on a mesh and the light/emmitter will be positioned so that the resulting reflections will appear exactly where desired... patch is in tracker: http://projects.blender.org/tracker/index.php?func=detail&aid=35069&group_id=9&atid=127 also a thread on BA: http://blenderartists.org/forum/showthread.php?289939-snap-align-to-reflection-option (if you find it useful or have suggestions on how to improve upon this please leave a comment here or on BA)
