Since 2007, Mozilla Labs has been incubating a project called "Weave Sync." It started with the idea of synchronizing Firefox bookmarks among different devices for a single user, but now it's doing a lot more than that, and according to Mozilla, it's ready for primetime.
It's now called "Firefox Sync," and it's slated to be included in the next version of Firefox. It's available now as an add-on.
Firefox Sync not only syncs bookmarks, but also passwords, tabs and other customizations.
With Firefox Sync, there's a single button to hit to restore your remote tabs and configuration. But what makes this synchronization application unique from competing software is that it's free and open source.
And according to Firefox, all of your data in encrypted with a "Secret Phrase," so only you have access to it.