i was there for Yanks series couple weeks ago...Fells Point for bars. take a cab from harbor , under $10. Power Plant for younger crowd bars (although i am 30 and didn't feel like the old guy), good dualing Piano Bar there i forget name, sounds gay but it's a blast.
was worth the $8.00 to go in Submarine , $ includes couple other ships also.
Federal Hill (park) nice for walk and good view of harbor
Bars outside stadium get pretty crowded few hours before game, on weekend anyway.
there is IMAX theatre in Science Museum, natural disaster flick that is pretty cool.
Museum with offbeat , unusual exhibitions. (like homeless guy who makes art out of spoons & forks, painting made by guy with no arms and no legs , etc) it's next to Federal Hill