Given the rather long meeting today, a break had never been so necessary. It reminded me of breaks with computer use. 

I have been using software to remind me to take a break while working at the computer. There are micro-breaks and normal breaks. Micro breaks are between 15-30 seconds giving you a chance to look away from the screen, have a quick stretch and check on your posture. Normal breaks are about 10 minutes which is good considering that you don't realise how quickly time passes. You can adjust the spacing between breaks for your needs which is great. 

For Apple computers Masa had recommended Time out (http://www.dejal.com/timeout/). For Windows and Linux I have found WorkRave (http://www.workrave.org/). I haven't been using WorkRave for long so I can't comment on it's interruptive nature.