I Want Sandy: Your very own personal assistant
I Want Sandy helps you stay organized and productive by working with emails to yourself and turning them into to-do's, address book updates and calendar appointments. It all works by sending an email and CCing Sandy on it. Sandy understands basic terms like 'reminder', 'lookup' and 'update' and will then sort the content appropriately.
If you aren't up to your neck already in to-do applications, I Want Sandy could be a beneficial application to try out. The concept is straightforward, and it could definitely save time on scheduling and calendar updates. It is currently in beta form, and is accepting signups to join the queue for a free account. In the meantime, if you want to get a feel for how simple and straightforward yet powerful its creator's web applications are, sign up for a free account on Stikkit, their little yellow productivity tool.