In the NPR link that I provided above, Dr. James Christina (podiatrist) says some interesting things about the benefits of barefoot (and minimalist shoe) running. He mentions that some college teams have their runner do some
of their training barefoot in an open field to help strengthen some of the muscles of the foot (and legs?). However, very few of these runners actually compete this way.
The Vibram site has a section on "barefoot" sports. Tennis is not
one of these sports:
I also came across another site that talks about playing tennis with Vibram minimalist shoes. The author, an advocate of these shoes, discusses both the positive and negative with regards to using them for tennis...
"While moving around the court is not a problem what ends up being a problem is sprinting to chase down balls. Sprinting in FiveFingers is easy, whatís hard (and painful) is slowing down quickly. Tennis is a lot of stop-and-go and spurts of speed. When you have padded shoes you donít really notice how much you rely on your heel to stop or brake your movement... "