I don't buy the "big white guy" vs. "little black guy" argument for a moment. If the smaller man has a handgun or some other equally lethal weapon, that guy is going to look like Godzilla to me and I don't care what race he is.
From what I've read and what others have posted, Zimmerman was following the young kid. Being part of a neighborhood Watch program, I imagine that's what he was supposed to do, and he did call it in before the kid was shot, didn't he? Assuming he did, did Zimmerman feel threatened? Unknown at this time. Is he racist? Possibly, alhtough that needs to be brought out during the trial. Did he intend to kill the young man because he figured he could get away with it and then claim it was self-defense? Again, unknown. There's an awful lot of supposition being tossed around here.
Now before anyone accuses me of taking the "big white guy's" side, I'm not on it. But I would like to know all the facts before making a judgment. The only fact I do know is that a young person died needlessly. Whether it was racism or an error in judgment is for the court to decide.
As a "white guy" myself who lives in Japan, I have also been subject to angry stares, occasional harassment, being refused by real-estate agencies, not being served in restaurants, etc. Not on an every day basis but it has happened from time to time. Even when I got married (my wife is Japanese) the real-estate agencies made up some BS excuse to exclude me out, as it were, so I'm no stranger to racism. However, anecdote aside, while Zimmerman comes off as being a thug, I would like to know more about what actually happened and not stoop to supposition.