Get your Backpack now.
Like many others, I recieved an email this morning inviting me to try Backpack. 37signals, makers of the uber popular project management 'webility' (web based utility) - Basecamp, has just launched another niche product.
Backpack is a personal organizer, where in you put your to-do list and other related everyday information. You can set reminders (email, SMS) on tasks that you've scheduled and even share your lists with others. Another interesting thing I noticed, is the clean use of XMLHttpRequest. Its an extremely useful tool for people who spend most of their time online.
I've signed up and have been using it for a little while, and for the first time, I'm seriously considering going in for paid service. I'm sure to find a lot more things to do with it over time.
Go on, try Backpack and see for yourself.