For unknown reasons Google Browser Sync has been discontinued in Firefox 3 and for Firefox 2 users will be maintained till the end of the year. Mozilla's effort, Weave, has still a long way to go until reaching a production state. Luckily, the latest update of Foxmarks brings that feature online again. Those already using it, check it's options. The others can get it either from https://addons.mozilla.org or www.foxmarks.com
The PIN has to be manually typed/activated in each of the boxes/installs that runs Foxmarks. Else, on an old Foxmarks install even if Pass Sync has been activated on another box, only the default bookmark sync will occur.
__________________
For safer browsing, use OpenDNS nameservers 208.67.222.222 and 208.67.220.220