Weave Sync is a prototype that encrypts and securely synchronizes the Firefox experience across multiple browsers, so that your desktop, laptop and mobile phone can all work together. It is part of the Weave project, which aims to integrate services more closely with the browser.
Source: Mozilla Labs
Interestingly this looks like a competitor to my favoured Xmarks, which backups and syncs my bookmarks across various browsers such as Firefox, Safari and IE. If you find yourself using various browsers, in various locations, this is invaluable.
