The Stephen Foster House is on Penn Avenue, just up the hill from Mullaney's. I pass it when I go grocery shopping in the strip. I always take the bus, because parking on the strip on Saturdays is either impossible or expensive. It's a big, brick house set back from the street. But there's a plaque where you can see it. If you take the 86B bus, you go right past it. Foster is buried in Allegheny Cemetery, which is also in Lawrenceville, Lillian Russell, and the infamous Harry Thaw are also buried there. There's also the Stephen Foster Memorial theater on Forbes Avenue in Oakland. Sorry to continue the drift.
Note, for the dirty minded, Pittsburgh's Strip district is a flat strip of land along the Allegheny River. It is the home of many fine bars, and interesting shops, but no strippers.