Blue Moon (about $20) is an example of an interval timer. It has a setting that repeats all day, and a gentle chime instead of the usual beep or buzzer. Gymboss is another popular brand of interval timer. Many sport watches and stop watches also have a repeatable timer that can also be used as a reminder tool to get up and move, to stretch, to hydrate, or to change your visual focus.
If you spend a lot of time at the computer, and need a reminder to hydrate or move, set your interval timer for 30 minutes to remind you to complete the desired action. Complete 7-10 days of the repeated cycling, and you will find your body cueing for a stretch or drink.
Need to hydrate?
Each time it buzzes, drink ½ glass of water, or every hour, get up and go refill the waterglass. A bonus move is that action causes you to look away from the computer,
You may discover you have more concentration and are accomplishing more. Besides helping you to detox naturally, drinking water is a great tool for achieving glowing skin, optimal digestion, better immunity, weight loss, better concentration and mental clarity.
A runner might want to hydrate at 3 - 5 or 8 minutes.
An excellent interval timer review can be found at http://www.runnersrambles.com/2011/01/product-review-gymboss-interval-timer.html.
She covers using the timer for time intervals in running, walk/run intervals and strength training.