Depending on how long ago it was it might be deleted. As for finding it if it's still kickin' then unless you've changed IP's anytime soon we should just be able to track it that way no?
Or even if you happen to know any of your old e-mail addresses that you may have used to sign up for that account to begin with. I suppose with any of those you can even cross-reference the entries to ensure that the right account is gotten.