If you really need to try and drink something other than water I would recommend Apple juice. It's really the only thing you can find that is 100% pure all the time. Even OJ isn't something especial if it's from MinuteMaid.
For taking breaks I would recommend a few applications a computer geek can download.
Mac OSX: TimeOut: http://www.dejal.com/timeout/, AntiRSI: http://tech.inhelsinki.nl/antirsi/
Linux: Workrave: sudo apt-get install workrave or http://dag.wieers.com/rpm/packages/workrave/
Windows: Workrave works for windows as well, Bigstretch: http://www.monkeymatt.com/bigstretch/