For as long as I can remember, I've used it to sync my bookmarks between PCs. With Xmarks, my desktop and laptop always have the exact same bookmarks (passwords, too), meaning the experience of using my browser is identical on both machines. What's more, whenever I bring a new machine into the mix, either for review or my personal use, a quick Xmarks installation puts all my bookmarks at the ready. It's ridiculously easy and convenient.

But there's an added perk to using Xmarks that many people overlook: The service keeps a (private, secure) copy of your bookmarks on the Web.

What's the big deal about that? Here's a personal example: Just the other day, I ended up spending the night at my folks' house, which was not a planned thing. In the morning I needed to access my blog tool so I could get some work done, but I didn't have my laptop. What's more, I didnt know the exact Web address for the blog tool.

Of course, because I'm an Xmarks user, all I had to do was hop on Mom's desktop, fire up the Web browser, and sign into my Xmarks account. Presto: There were all my bookmarks, organized just like on my own PC. I can't say I need this feature often, but when I do, it's absolutely invaluable. And it's among the reasons Xmarks remains an indispensable part of my computing life.