So here is my clever little idea;
People are going on leave all the time, be it for a couple of days or weeks. I always found it a little difficult to know who is around, when, unless you are checking the leave boards non-stop and pretty much taking note of when everyone is away.
What I'm suggesting is a "drop box" of sorts in your profile where you could pick your "activity status". You'd be able to chose from "Active, Leave, Semi-Leave" and whatever else there is to put.
From there, your activity status could be displayed somewhere near your avatar, or there could be a link which brings you to a list of all people "active", all people "on leave", etc.
Maybe this is a little unecessary or pointless; but unless most people keep record of who is away, and who isnt, I imagine it being a handy little thing.
Embrace it, bash it.