Allows the Context module to change the theme of the site. 1.x is for use with Context 2 and is no longer being actively maintained. 2.x is for use with Context 3.
NOTE: Because of the way the Context module interacts with Drupal core, you can only use Context Reaction: Theme with the "Sitewide" or "Path" conditions. I recommend using Pathauto in combination with the Path condition for most use cases (especially things like node types, etc).
UPDATE 24 JULY 2013 - This module has been dormant for some time, but now has a new maintainer (kpa) - I'm working on a stable D7 release, and may then address D6 issues after that. Patches and reviews welcome, particularly on D7 version.