I use Math.SE from public computers quite often. However, I have few misgivings while logging in my Gmail accout (which I have to log in as I use that id from Math.SE) in public computers. Could we add a feature which will enable us to log in to our Math.SE account without entering our Gmail passwords and email id while on public computers?
You can have multiple OpenIDs associated with an SE account. Just add another OpenID from a different provider and use that one to log into SE from public computers.
You should also always use the incognito/private mode of the browser on computers that are not your own, the whole OpenID stuff doesn't behave exactly as you would expect when logging out, and it is rather easy to accidentally remain logged in.