Anno 1998. I discovered the Internet and started to create websites. On my research for good sources and examples I visited hundreds of websites, one of them was selfhtml.de; the one and only website I still remember because of the domain. Many many many other (sometimes incredibly long) URL's were lost. The bookmark feature of the browser allowed me to "remember" the website.
As the years moved on, I also started having more devices. A laptop, two desktops at home and a computer at work. No smartphone then, as the Nokia 3210 was barely capable to do anything else than SMS. But what already bugged me was that some bookmarks you had at work, you wanted to use back at home, but without the bookmark one didn't remember the URL.
Once Mozilla (not Firefox then) came out, it allowed to save the whole bookmark list as an html or text file to then import it on another computer. Finally bookmarks could be "saved" and be used on multiple computers. But it needed manual interaction and to do that every couple of months (and to regroup the bookmarks) was a lousy task.
Now finally I decided to give Firefox Sync a shot. It comes in by default with the new Firefox 4.0, so no addon-installation is necessary. You re-group your bookmarks, create nice folders, separators and so on and then... you Add A Device. This can be another computer using Firefox or your Smartphone. I've tested it and it rocks! Fast synchro and now I can have my bookmarks everywhere.
Only one thing should be well thought of: Do you want to synchronize your password or history as well? Should passwords, you have used at work, be synchronized with your home computer? Should your browsing history of "adult" pictures from your home computer appear in your work computer's Firefox history? One has to decide that for himself. ;-)