[jackowayed]

Also similar to something Google often does in meetings (according to some article I've read on here). They just project a giant timer on one wall. I can't remember if it's usually timing the meeting as a whole or one section.

[felideon]

I prefer the Meeting Ticker: http://tobytripp.github.com/meeting-ticker/

[prawn]

Someone should make one of these as an iPhone app for people stuck in boring conversations, only it shows an emailable invoice at the end based on the time wasted. ;)