For many people, lifecasting is just too much of an invasion of privacy.
So why not consider "Lifehinting"? The idea here is to give clues as to what your life is like.
For example, you could do this by an algorithm that transforms a lifecasting feed into abstract animations, perhaps resembling VisualID Scenery. Similar sorts of activities would result in similar sorts of abstract animations.
After a while of doing this, your friends will start to get clues as to the sorts of things you do -- at least, for those activities that they are familiar with.