How valuable (or not) do you think daily stand-up meetings are?

If you're not familiar with it, this refers to a daily meeting often pushed by Scrum adherents (and some other general agile proponents). The idea is that you hold a daily meeting, timeboxed to 15 minutes, and in which everyone must stand (to encourage people to be to-the-point).

In the meeting, you go around the room and each say: - What you did yesterday - What you plan to do today - Any blockers or impediments to your progress.

Do you think this practice has value? Has anyone worked at a place that's done it, and what did you think?