I've been to Pitt from Greyhound many times. The bus station is in downtown Pittsburgh, but there are cabs waiting outside. If you decide to take a cab directly to Oakland, where the dental school is, it'll cost you around $15 or so (prices may have gone up since the last time I took a cab to Oakland, so you would want to bring more just in case).
As for Temple's group interview, it's nothing to worry about. After lunch, they will call out names and divide you up into your interview groups and you follow a dental student to where your interview will take place.
My interviewer basically read out a question, and kind of asked "so who wants to take this one first?" and we all go around saying our respective answers. It does suck to be the last to go when all the "good answers" have been said already, but it also gives you good info for your own. Good luck to you guys!
Alfie, let me know how Pitt is! I'll be interviewing there on the 28th!
