How to force ssh client to use only password auth?

If I use pubkey auth from e.g.: an Ubuntu 11.04 how can I set the ssh client to use only password auth to a server? (just needed because of testing passwords on a server, where I default log in with key) I found a way: mv ~/.ssh/id_rsa ~/.ssh/id_rsa.backup mv ~/.ssh/id_rsa.pub ~/.ssh/id_rsa.pub.backup and now I get prompted for password, but are there any offical ways?