I feel the exact same way. For a long time now, I've set up facebook friends in groups, and I use twitter but only with best friends, never coworkers, roommates, former friends, etc... Twitter is my outlet.

I was working on a site like twitter but with much more anonymous features and hierarchal posting interactions, and security features, largely motivated by both the iranian election and arab spring, but I got sidetracked and bored of the project pretty quickly, ultimately realizing that there's not really an elegant all-encompassing solution to the situation.