Move your Xmarks to your own server
Even though Xmarks is shutting down due to competition from the built-in bookmark syncing features in Chrome and Firefox, it can live on ... on your own server! The only catch is that this trick only works with Firefox for right now, but Xmarks could open source their code when they close down and open the door for a cross-browser build. But I digress! Here's how to get Xmarks up and running.
You'll need some server space and the ability to set up a WebDAV directory. Once you've set it up, you'll need to go to your Xmarks settings in Firefox and enter the url of your new directory. Then, still under Xmarks settings, hit the Synchronize Now button.
Bada bing, bada boom! You've set up your own hosted version of Xmarks! You'll have to enter the server information and hit sync again for each Firefox installation you use, but that shouldn't take very long.