I used to work at Cisco where every meeting was delayed as every participant would set up their laptop and then proceed to type, surf, "do email" etc. during the meeting. Crazy. I work at a big bank now where the laptop in meetings thing is frowned upon. The meetings generally start on time, are shorter and people generally respect meeting start and finish times.
I'm very surprised to hear about people bringing laptops to meetings. I've never seen this happen (where I live). It seems to be disrespectful and contraproductive. You're there to talk and think right?
At the fairly large (2000+ employees) software company I currently work for, we use the laptops to drill down bug defect lists, customer/partner requests, look at waterfall development schedules and gantt charts, random email responses, wiki pages with specs and reqs, and use collaborative notepad to write up status updates.
Some people are working (coding, testing, answering customers, etc.) while others are surfing/facebooking/tweeting; but the latter doesn't really last at this company. They flail pretty quickly, likely prior to their first major product release.
