My commute is about 19 miles each way with my normal commute. If I'm training for some ride it's about 19 in the morning and if I go the long way home with my friend it 50 home. Usually it's 19. :-)
Normal:
http://www.bikely.com/maps/bike-path/My-Commute106523
Long way home:
http://www.bikely.com/maps/bike-path...-home-long-way