I'm not sure it's possible, but I would love an App.net client that let's me use a date/time "slider" to move through my timeline. Then, when I'm 2 days behind, I could move to a more recent timeline position.
@duerig it is tough sometimes, particularly trying to keep multiple discussion threads desperate in my mind. I usually read threads forward and the ignore them as I scroll back. I've dreamed of an ADN client that hides "seen" posts on the fly.