I'm a numbers person, so I like logging my workouts, charting my stats, etc.  One of the neat social networking sites I'm on (DailyMile) generates an annual report summarizing all the activities you log on the website (this is the free version - there is a new paid version of the online training logs).  I'm still deciding on whether to do the paid version.  A great way to recognize that it's worth it to put in the work.