Syncing has been a standard feature of Apple’s Safari browser for some months now, but you need to have MobileMe for it to work. And Firefox users could download add-ons like Xmarks (previously called Foxmarks) to get the functionality, but with Chrome it will be built-in, and most importantly, unlike MobileMe, free. Google notes that the bookmarks are stored on users’ Google account alongside Google Docs and sync via XMPP. For now available only in dev version of Chrome.