As expected, the latest Firefox 4 nightlies feature Firefox Sync, Mozilla’s service that lets you synchronize your bookmarks, tabs, history, passwords, preferences, and other customizations among devices that support Sync: Firefox for desktops, for Maemo devices, and Firefox Home on the iPhone.
Just like the original Firefox Sync extension, its preferences are integrated with Firefox own options and is only noticeable by a small icon in the status bar.
If you don’t have an account yet, this is a good time to get one for free and start moving all your browsing data to the cloud. Just install Firefox Sync and follow the instructions to set your account in a few seconds.
Sync fucntionality will be available in the next Firefox 4 beta update, expected for later this or early next week.