I did. Once. I wouldn't do it again.
Operations mgt will take you into production scheduling/management, purchasing, or materials mgt. Think long hours under normally pretty stressful conditions. Being that it is also normally in a manufacturing environment, it's also very volatile--meaning no matter how much you bust ass, if your company loses a key customer, or gets bought out, or ships their business to Mexico where they can pay someone $.10 a day to do what we are doing for $10/hour--you're left without a job. I wouldn't say this if it hadn't happend to me--twice.
I first graduated as a business major, did purchasing and scheduling for a large healthcare supplier for a while, and then went back for mechanical engineering, then ended up in IT when the manufacturing-engineering gig went TU. I was in the mfg side of engineering, and as such, ended up dirty, tired, underpaid, and worked with alot of people who were morons, but though they were God's gift to--something. The environment I was in sucked--that's why I left it, although certainly all engineering isn't like this. I contracted a few years in IT for myself and made decent cash (much better than engineering)and was able to save a lot of it. Were I to do it over again, I probably would have skipped going back for engineering and done an MBA, or a even better, gotten a law degree. In other words, if you're sharp, you'll figure out soon enough you're not going to get rich working for someone else or some company. They don't have your best interests, or really, any interests past what you can provide for them, at heart.
Manufacturing in the US is going away. We are (quickly) becoming a service oriented country. The trick is to provide a service that everyone needs, and has to pay highly for. That way, you can schedule your work around your life, and not the other way around. Being a lawyer I think provides that, as does some areas of IT--at least it used to. I found the quick way to kill a love for something is to do it for a living--so I rarely am "technical" in IT anymore. I got tired of pushing buttons and setting up VLANs. I (attempt) to tell others the right thing to do.
So my long winded answer is that some people thrive in OM, others ended up like me, burned out on it and not beleiving I ever did it to begin with. I have seen so many "TQM" and "SPC" falvors of the month come and go, it's just a fad anymore, and every industry has their own with their own buzzwords. The good stuff is common sense and hopefully sticks around; most of it is just fluff that has alot of buzzwords and keeps a consultant employed for awhile until he gets done selling his snake oil.
Good luck.
edit--I re read that and MAN did it sound depressing and cynical. Sorry--I didn't mean for it to be. It was a hard day, and this is typed after only 1 beer.
Career Advice: Operations Management or Industrial Production Management 
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