Hey nspatafora ,

I commute between Philadelphia and NYC every day.
Each month, I purchase a monthly ticket which i just show to the conductor on board.
My pass is good on most regional train service, and for $10 and I upgrade to off peak metroliner service.
There is no need to visit the ticket office before each trip, In fact I usually purchase my ticket from Quik-Trak, so I have never been to the ticket office in about 2 years or so.

As I mentioned above, tickets are good for most regional service. Check out the link below which explains in detail what trains accept monthly or "smart passes"
http://www.amtrak.com/servlet/Conten...am2Copy&ssid=6