I'm going to be starting the couch to 5k program over the weekend. I haven't run for 14 months, so even though my last run was a half marathon I am going to treat myself as a beginner. I found this podcast http://www.ullreys.com/robert/Podcasts/ that does all the interval timings for you. The music is not really to my taste, but it will be better than messing about with a stopwatch.