Keep pinging people. Asking for updates on a roughly weekly basis is a good thing. You should presumably have at least one contact from when the interview was scheduled, and hopefully you met someone during the interview and have e-mail addresses - ping these people as well.

Also, keep looking. A successful interview, even with reassurances from your contacts that things are moving along, isn't worth very much. If you get another offer in this period, you have a lot more options.