Source: http://lifehacker.com/5890690/sync-your-desktop-between-computers-with-dropbox
If you use multiple machines, you may be frustrated by the fact that your desktop—where many of us keep our current projects—doesn't stay in sync between computers. While you could drag the files to your Dropbox manually, reader tpflanz has a simpler solution: just move your Desktop to your Dropbox.
I sync my documents through Dropbox, but my desktop contains a different mishmash of icons on each computer. The problem is, my desktop actually serves a purpose in my workflow—whether as a mini to-do list or a dump for works in progress, and forgetting to drag files over when I switch workspaces is a constant problem. Tpflanz' handy trick works on Windows, Mac, and Linux:
I don't always work from one physical location, so it is a bit of a chore to make sure I have transferred files to a location (such as USB drive or FTP site) so I can access them later. As well, should I really need to pull out my laptop to grab a single .php file or .psd? I don't think so.
Using Dropbox as my desktop allows everything I am working on to be available everywhere I work, without even thinking about it.
You can either symlink your Desktop as described in our Documents-organizing feature, or (if you're using Windows) literally move the Desktop's location. Just head to your User folder in Windows Explorer, right click on the Desktop folder, choose Properties, head to the Location tab, and then enter the path to your Dropbox folder. After doing the same on your other machines, everything will stay in perfect sync.
This trick should have been obvious to me, but I never thought about it. If you actually use your desktop to house items you'll need later, this is a really great way to make sure you don't forget about any of it. Do note, however, that if you have application shortcuts on your desktop, you'll want to make sure they're stored in the same place on each machine, or they won't work. Hit the link to read more.
My Favorite Use for Dropbox: Synced Windows Desktop | Travis Pflanz via #tips