This is an easy cheap way to get to Philly, DC, or Boston. Chinatown is full of incredibly cheap busses that run back and forth to both, and the Philly ones run all day long... and it's a shockingly low $10 round trip.
The one I took is called "Dragon". You don't reserve, just show up at the East Broadway Mall on East Broadway in Chinatown under the Manhattan Bridge. There are ticket desks all around the outside of the building. Maybe you should stop by one day and pick up a schedule. It's a fun neighborhood to check out anway. Just head down Bowery until you hit E. Broadway (it's sorta near Canal), hang a left, and walk a few blocks until you're under the bridge.