CodeIgniter 3.0.6 Released

This is terrible advice. See the original post at the top of this thread and read the upgrade notes provided. In particular, 3.0.3 has additional tasks that should be performed, but so do several of the other steps. Just copying over your 3.0 system folder and walking away is not advised.

This feels like a silly question, but if I'm on 3.0.0 do I have to upgrade to each previous version, all the way up to 3.0.6? Or can I upgrade straight to 3.0.6?

Just copy system folder in 3.0.6 and paste to replace your system folder 3.0.0 ... upgraded