+1 because I think that this is an important question.
It seems that the intent of this method is to increase productivity. In saying this, nothing kills productivity more than deadline tension. Having to constantly look over at the time would no doubt have this effect.
Well, this morning after reading this I threw together a script in 5 secs to do this for me.
I'm using OS X and like everyone this means I have Growl installed for various applications. I figured that it should be easy enough to announce my times using that.
Looked around, found the commandline tool growlnotify and 5 seconds later...
And for those of us with Linux (needs notification-daemon and libnotify):
#!/bin/sh
while true; do
sleep $((30*60))
notify-send -i applications-games -t 60000 "Play" \
"Hey, it's time to take a break\!"
sleep $((30*60))
notify-send -i applications-office -t 60000 "Work" \
"Now get back to work ..."
done
I'm a little baffled by why people feel that finding a device (hardware or software) that will countdown a specified interval of time and announce the conclusion of that interval is so hard.
The venerable egg-timer has been around for a long time, and would work just fine. You can even setup OS X to use text-to-speech to announce the time on the hour and the half-hour (if you are doing the 30/30). Not to mention that 'countdown clock' software is practically a 'hello world'-level programming project (if you throw out all of the bells-and-whistles like sexy notification animations, etc). On Linux, you could setup a script using 'at' and 'zenity' to remind your of time intervals... etc ...
I personally find that having a deadline increases my productivity. If I feel like I have unlimited time to work on something, it rarely gets done until the last minute.
It seems that the intent of this method is to increase productivity. In saying this, nothing kills productivity more than deadline tension. Having to constantly look over at the time would no doubt have this effect.