Trying to install Pydev for Eclipse somehow got me into a funky state with some corrupt jar files and I kept receiving the error below:

Error
Tue Sep 18 19:27:38 CDT 2012
Unable to read repository at file:/C:/Users/Mark/dev/eclipse/p2/org.eclipse.equinox.p2.repository/cache/content564205554.jar.

I simply went into the “Available Software Sites” preference, highlighted Pydev and Pydev Extensions, then I selected Reload and voilà.  The problem went away.  I guess using somehow the proxy on my internet sharing phone went gefunkt.