Do you use more than 1 computer or do you use a dual boot system? If so you will have a problem accessing your bookmarks etc when you change computers. Google has an answer for you, Google Browser Sync.
It only works with Firefox but allows you to share your bookmarks, history and passwords between each system. It is a Firefox extension, one of the advantages of Firefox is the ability to customise it with extensions.
Of course if you share computers with someone else you will need to consider the security aspect. You may not want to have your passwords available on a computer someone else uses. If you are the only one using them Browser sync is incredibly handy. I use a desktop which I dual boot in WinXP and Linux and I use a laptop too. With Browser Sync it doesn’t matter which system I am using Firefox has the same bookmarks and passwords etc. It even remembers the last page I used and will return there if I wish.
One of the best Firefox extensions and it works fine in Firefox 2. Download it here.