Visiting Philadelphia this weekend

I am visiting Philadelphia this weekend and will be there for a little more than a week. Besides the obvious things to do:

• Eat at Geno's and Pat's

• Run up the Rocky steps

• Capture that Brazilian murderer

Okay, I may attempt to do one of those three. What non-touristy things are recommended? My only plan so far is to go to a Phillies game next Friday.

I'm coming from Florida. Can I get away with wearing mostly shorts and T-shirts next week?