I went in search of an application that would synchronize my bookmarks. It needed to meet the following minimum specifications:
Sync2It met all of those requirements, and after using it for a couple of weeks with no real major issues, I bought it. Diigo and Google bookmarks were very good applications, too, but didn't pass some portion of my needs. I did email the author about some enhancements I'd like to see to make Sync2It even better. I'd encourage you to try and buy Sync2It. That way, maybe these suggestions have a chance of getting implemented.
Here's hoping this will let me focus on saving and categorizing bookmarks, as opposed to constantly leaving stray bookmarks around and needing that one bookmark on the one machine I'm not currently using!
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.