I am constantly trying to find ways to keep data in sync. My weapon of choice for the past few years has been various palm pilot type devices. I tend to stick with the palm as syncing to linux has been extremely easy over the years with Jpilot and Evolution.
After a recent rebuild I was looking for a better way and did some research on SyncML which is basically a fancy way to backup your data (Contacts, Calendar, Notes, Todos) on your cell phone in case bad things happen.
Over the past week, I have been using a combination of a SyncML client for the Palm, Synthesis and a free web based host O-Sync. Everything seems to be working great. I am able to sync my phones data to a website that I can then reference from any computer.
There are a few concerns on the usability of O-Sync and the ability to export data, but the ability to wirelessly sync my data is well worth the extra backup steps that are needed.