Anyone know if its possible to use a Yubikey for sudo as well?
We still use it for SSH and its great!
If someone steals the key, they can't really do anything with it. They can't sudo because the session is locked. They can't use it to log in your web accounts from other computers because websites ask for a password/pin in addition to touching the yubikey.
PS: you should always have a backup yubikey (or, better, two)