Fun around town, for $10 or less: FRIDAY Going Underground: The Underground Film Series at the Ukrainian League of Philadelphia (800 N 23rd) presents Radiophobia and Have You Ever Heard About Vukovar? at 8PM. Free Cellos Are Cool: Cellist Monica McIntyre performs at The Philadelphia Society for Art, Literature and Music (5841 Overbrook Ave), 8PM. $10 SATURDAY National Pretzel Day: In honor of this auspicious holiday Philly Pretzel Factory will be giving out three free......