Have to zip up to Philadelphia on Amtrak and wanted to store a bag for a few hours. Does anyone know if there are lockers/baggage check?

It looks like they have a checked baggage facility: go to amtrak.com, click on Stations, enter PHL and follow the links under Station Services.

Oh, and I should also say that you probably need to show them an Amtrak ticket in order to put your bags there. (That's the case at NY Penn Station.)

Usually this is not available at most stations and airports since 9/11. However, when i was there a few months ago I noted some lockers over in a corner. I did not check them out so could have been not for public use. Unless one of the posters says differently. The only way would be a phone call to station office..
good luck

It's true that most stations don't have self-service lockers any more, but they do have a (paid) checked luggage service that is very much still in use at many stations; that is what I was referring to.