Love it!
Thanks, you just reminded me that I need to clean up my bookmarks!!
How I did it: A folder for Work and a folder for Personal, with many subcategories to Personal. Both folders sit on my toolbar along with 10 frequently used links (email, RSS reader, Facebook etc.) Everything's on the toolbar rather than the bookmarks menu, which is empty. Finally I shared my bookmarks between my machines using Xfire, so that I've got the same set on each user account, updated automatically.
Lessons & tips: Be ruthless in cutting bookmarks you don't really need anymore.
Resources: Xfire (bookmark sharer).