I heart rebase, but I haven't figure out how to keep a remote branch in synch, I rebase and when I try to push to the remote branch it fails, I sometimes end up just creating a new local & remote branch :/
(or if local-branch-name and remote-branch-name are the same:)
git push --force remote branch-name
(N.B. if there's a chance that anyone else is working on the same branch, then think twice before doing --force, because you may spoil their afternoon. Read 'git help push' for more info.)