CSS Only Themes for Drupal 7

I didn't get to contribute much to Drupal 6 before it happened.  I was still learning how to use the toolset the Drupal community uses for these things, and after one successful attempt to contribute to core, I decided to focus my attention on contrib for a while.  It's been more than a year since that time (probably closer to two) and I'm much more comfortable and familiar with these tools, as well as having a much better idea of what it is that Drupal is "all about".