“Firefox Sync (formerly Labs/Weave) gives you secure access to your bookmarks, open tabs, and browsing history from any computer, as well as mobile Firefox and Firefox Home for iPhone. For details, see the Firefox Sync website. ”
Its possible to run it on your own server, instead of using mozilla servers!
ymartin59 has built minimal weave server in PHP and it works very good:
Installation is easy and fully described in a README inside the code archive:
Firefox setup is not so obvious: