Future Me - Send an email to your future self
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Dabble Me - Your own private place to write. A journal/diary to help you remember what's happened in your life.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Letter to Yourself - Send a physical letter to your future self
Basecamp - A simple and elegant project management system.