In the past, I had a small whiteboard on my door I could write my away messages on (lunch, meeting, vacation, etc) and people could leave short replies on it wh

In the past, I had a small whiteboard on my door I could write my away messages on (lunch, meeting, vacation, etc) and people could leave short replies on it when they didn't want to send an email (call me, borrowed your charger. It worked great but only really works when you work in an office all day and can update it when you get back from wherever you went.