Getting a ride to Philadelphia or south is no problem. Going west or north is a bit more difficult.
Duncannon (Appalachian Trail)
Accessing the AT in Duncannon is super easy hitchhiking. Taking a cab will set you back $60 so under no circumstances do this!
From the train station, head out and back under the train track on Market Street. Take a left on the 230 and follow this road northbound. There is a gas station on the right side quite soon after the station, but if you continue on down for another 20-30 minutes you will hit a better one. This gas station is just after a major junction, so cars slow down by it. You can stand here with a sign to Duncannon or ask people at the gas station. The journey takes about 30 minutes to reach Duncannon.