Hmm... I don't compartmentalize much. The only times I do are like... I have a friend who's very conservative/religious and other friends who are constantly dissing religion. They know about each other and have as good as told me they'd get into a conflict on purpose. i know them, know they'd leave the meeting offended, and don't plan to introduce them Besides, they live so far apart it's highly unlikely they'd mean on their own anyway, so it's hardly like I'm "keeping them apart", I'm just not making an effort to bring them together, if that makes sense.
Other than that, I have to say that I know from personal experience that compartmentalizing is a BAD IDEA. I don't want to dredge up the gory details, but it basically ripped my family apart when I was 13.
I personally believe you need to integrate your life, that strong relationships bring two families together, that true friends accept all aspects of you, and that you should try to be yourself in the working world as much as possible. Certainly you would generally behave differently at home than at work, but it shouldn't be a disaster for those different parts of your life to meet. I think life in general is happier and healthier that way, but then this is just what works best for me.