Small world: the person behind me in line today at Walgreens was a friend from college who I hadn't seen in several years.
Their e-mail address is something like firstname.lastname@example.org, but to protect their identity, it may not be that. But I liked the idea of "i am n'th" as a username, and I wondered how low of such a username was still available on google.
The answer, it turns out, is twelfth. Lower than I thought. Assuming I spelled that correctly.