Why pay to exercise? Grab a pair of sneakers and learn to run.
* http://www.runnersworld.com << learn to run
* http://www.hundredpushups.com << learn to do 100 pushups in 6 weeks.
* http://news.ycombinator.org << learn to stop wasting far more time than is necessary on this site xD
I'm 2/3 on that list.