people have to make the distinction between prejudice/bias, ignorance, and racism, which I see getting confused for one another a lot. People are prejudiced, all people are, and prejudice expresses itself in many ways, not just based on race, but religion, culture, social status, etc... When someone expresses a biased viewpoint that relates to race, it isn't necessarily racist, tho it will always be called cism by most black folks.
In some cases bias/prejudice is the rational, like Dinesh said about cab drivers, and other times bias/prejudice is based on ignorance or lack of information. In either case, ignorance isn't necessarily racism either.
Racism is a belief that one race is superior to another, and the superiority is rooted in the actual racial component itself. So its more than prejudice. To say something like black people have a culture of laziness... immediately black people are offended, crying racism. If you connect the trait with the race, that's racism... i.e. black people are inherently lazy, as a matter of birth, genes, DNA, it cannot be changed thru any behavioral modification, they are just inherently this way. THAT IS RACISM. If you don't make that connection, but instead just make the observation that there seems to be a culture of laziness among blacks, that may be ignorant, and you may behave in a prejudicial way as a result, but that's not necessarily racism people!
I'm not saying any one of these things is right... but prejudice is in human nature, its a part of survival instinct, so that's not going anywhere. Instead of always crying racism every time a non-black person expresses themselves on race, understand what's realy going on first. You may actually end up learning something, or teaching someone else something.