I spent much of the 1990's supporting the Iraq NFZ's and did the same in the Balkans.

Regarding Libya, yes, tactically, it's pretty easy as far as the threat goes. Practically, it's very resource intensive. But what's the point? What's the objective? If we want the rebels to win, there are lots of ways to do that with a lot more surety than a NFZ. To me, cynical bastard that I am, it looks like something from the good intentions fairy - a low risk way to be seen as "doing something."