Until a couple of months ago there was a site called cpan2 which acted like a fast and enhanced mirror of search.cpan.org.

However, it seems to have died now. Here is a news release about it.

At YAPC::EU Brian Ingerson was talking about his plan for NAPC a type of Napster for CPAN. I don't know if there has been any work done on it however.

--
John.