Improve yourself with crontab and growlnotify

Its been a very long time since I last posted.  I've moved, changed jobs, major technologies (Windows / ASP.NET / C++ to Mac / Rails), had twin boys and am now working from home.  Working from home provides some great opportunities (family time instead of commute time being the big one).  I've found that I need help making sure that I take a break and step away from the computer occasionally during the day.  Also, I'm a skinny ex-cyclist who doesn't like to go to the gym, but does want to be stronger.  Enter GrowlNotify and crontab to the rescue.