I'm on a committee for the university, a small one, with a closely defined task. It's a lot of work, but it's fascinating. I don't often get to chat with people from really different areas about our common work, but we have a chance to do that in the context of our task, and it's quite an education. Something I take for granted here in my department, in my college, someone in another department or another college thinks totally differently about. Stuff they spend a lot of time thinking about, I may not.
It's also, I hear, sort of hard to get faculty to agree to do this extra task. I mentioned that to my chair, since we were having lunch today, and zie said something along the lines of, well, it counts for service, right? But I pointed out that it doesn't count for service in our department, since I'm still expected to carry my full department committee load. (I didn't point out that I had tried to get out of some of my department load in a conversation with hir because of this, and zie had said "no.")
Still, at least it's a really interesting committee.