Beeminder - Beeminder
Bucketlist.org - Log and catalog all the stuff you want to accomplish before you expire.
GoalsWon - Human accountability coaching for busy people
List Challenges - Earn points for your life experiences. Find lists that interest you, and mark off what you've done.
Coach.me - Coach.me is a coach that goes everywhere with you, helping you achieve any goal, change any habit, or build any expertise.
Life Listr - ***AS FEATURED BY APPLE***