Two good ways:
1. Webbased. There are offers either from Google or based on MS Exchange that centralize the data on Internet while allowing access from anywhere.
2. A paper calender and notebook in stead of using 4 devices. That's a uniform and centralized storage also, easy to take with you.
Kees
I'm sure my position is a common one: a crazy busy life. I am looking for software/apps to help with juggling everything and syncing my calendars, contacts, tasks/to do lists with four electronic devices:
1. Droid
2. Ipad
3. Home laptop (pc)
4. Work computer (pc)
Any software suggestions/apps that may make life a little bit easier.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic