Recently at the Seattle WordPress Meetup, we heard an excellent presentation by Mark Root-Wiley of MRW Web Design on how to use child themes when developing a WordPress website.  In my work developing WordPress themes, I frequently use child themes, basing them on the default TwentyTen theme. The reason for this is to get a basic template structure that can be turned into any style I want. Some themes are just small adaptations of the TwentyTen theme and are very recognizable as such. Others, have a totally different look and feel.  To get an idea of this take a look at these two websites:

Leadership Navigator

Leadership Navigator


Vital Content PR

Vital Content PR (developed theme for Blue Sky Projects)