How do I compare two git repositories?

Since the two git repositories start out the same, you can pull both into the same working repository.

$ git remote add cvsimport-a git://.../cvsimport-a.git
$ git remote add cvsimport-b git://.../cvsimport-b.git
$ git remote update
$ git log cvsimport-a/master..cvsimport-b/master  # in B, not in A?
$ git log cvsimport-b/master..cvsimport-a/master  # in A, not in B?