This is an overview of RPy:
http://www.daimi.au.dk/~besen/TBiB2007/lecture-notes/rpy.html
While I've never used it, I can definitely see doing so, as I've recently become more and more a python programmer.
R-Cookbook.com is a collection of "recipes"--problems, solutions, and working examples--contributed by the R community in order to share code, promote the use of R, and make the learning process more efficient for new users.