Login or Logout or Sign in or Sign out

I don't think it really matters much one way or the other, though I do like the list of sites and they way they have chosen. The only one I do not like how it does it is twitter, login/sign out... though with the recent redesign they have changed it to sign in/sign out.

There's a 3rd element that goes hand-in-hand with these:

Create an Account

Sign Up

Join

Become a Member

Sign in/out makes more sense to me because it focuses on user activities. Logs are back-end functions that users shouldn't have to think about.

Whatever happened to logoff anyways?