I sent another email. I hope I'm not coming across as someone desperate for the position, but rather as someone who's really keen on working with them!

If I don't hear back, I'm guessing I should throw in the towel. I have their phone numbers though...would it be out of order if I called them, say, a week from now, if I don't get an email reply? Or would that be creepy?

The optimist in me has been crossing fingers in the hope that my application fell through the cracks, as you put it. I will be totally dejected if I don't hear back (at least an outright rejection will put my mind at ease!), especially as I had believed I had built quite a rapport with my latest interviewer who seemed keen on having me on-site.