"I have a bunch of single-use Gmail accounts for the usual
things, like account registrations, site administration, newsletter
subscriptions and the like. If you have this same situation, you
know that (unless you possess unusual patience) it's not easy to
serially open up multiple Gmail accounts if you have saved the
login information for an auto-login. Oh, and forget trying to have
multiple parallel Gmail accounts signed in, it's one-by-one or
nothing. Well, until now, that is..."