How cool would it be if you could take the data you input and see a chart that shows where you spend the most time?! For example, my chart would probably show that I spend far too much time at work. It'd be interesting to see your friends charts too, almost like a social experiment on where people are spending their time the most.
I think clicking on a person's icon/avatar, regardless of where it is on the site (e.g., not only in the "what's happening" section) should take you to that person's profile.