Funnilly enough I'm hoping to go to the states next year and visit a few 'regular' places rather than the usual tourist traps (Disney world etc.).
As a massive fan of The Wire I asked myself would i like to see B-More and locations from the show.
Considering that I'm a soft as shite middle aged white man would i meet serious hostilies?
Would you go in my situation?
If you rent a car and drive around during the day, you should be fine. Even walking around some areas is probably OK, but leave your wallet with extra credit cards etc. in your hotel room, and don't go flashing expensive camera equipment.
Just as important, in some of these areas, is that you look like you have a purpose being there. If you stand around gawking like a tourist, especially if you're a white guy, you'll attract someone's attention pretty damn quickly.
While i really grew to love Baltimore during the 7+ years i lived there, it's not a city that rewards casual tourism or short-term visits very much. It's not like New York or San Francisco, or even Washington. There aren't as many obvious "destinations," and the main tourist area around the Inner Harbor is a fucking awful trap of bad shops and kitsch.
The CityPaper (the paper you linked to) is Baltimore's free alternative weekly newspaper, and is a good place to start for information. If you follow it online for a while, and check out the dining and entertainment sections, you can get an idea of some interesting things to do and places to go. The town has some great bars, good food, and interesting areas. If you decide to go, start a thread and i'll be happy to offer some advice and places to go.