Lancaster Brewing Company, as mentioned, about five or six blocks away: http://www.lancasterbrewing.com/
Annie Bailey's, right next door to the hotel/convention center: http://anniebaileysirishpub.com/
Quip's Pub, a block down the street from LBC: http://www.quipspub.com/
As always, if you're out walking at night, be careful! FWIW, there is no reason to walk south, west, or due east over a block of the convention center! ;-)
Looking forward to a good show!