Source: http://handgunlaw.us/documents/PA_AG_Letter-50.jpg... we [the AG's office] have been advised that some law enforcement agencies in Pennsylvania, including the Pennsylvania State Police, are taking the position that our reciprocity agreements with other states do not confer a right to carry a firearm in Pennsylvania on those license holders who do not reside in the state in question...
There is some good news:
The Sheriff of Centre Co. PA., Denny Nau, will issue Via mail to Non Residents of Pennsylvania. (You must have a permit from your state of Residence if your state issues permits.) You can apply in any county but some sheriffs in PA will not issue to non residents though the law says they have to. The easiest way to obtain a PA Non Resident Permit is to contact the Sheriff of Centre Co and they will mail you everything you need and you can do it all by mail.
Source: http://handgunlaw.us/documents/NonResidentPermits.pdf
-Brent