I suspect many TUAW readers find themselves in the same situation that I am in: I use a desktop and a laptop. I often find myself wanting to move files between these two machines, so here's what I do: switch to Finder, click on the shared Mac I want, navigate to the folder I'm looking for, and then track down the file I want to copy there and drag it over. I could drag a folder from the other computer to my "Places" sidebar in Finder, but honestly, I just never do.
What I wanted was something quick and painless. I tried to whip something up using Automator and Folder Actions where it would copy/move files saved in one folder to the other machine, but even that would get messy. Most often I don't want to move the file, I just want to copy it. I could put the files in Dropbox, but some of these files are sizable (i.e. the 30+ MB iMovie update). To use Dropbox for this would take a long time.
Turns out that Dropzone offers the perfect solution: by enabling FTP on both Macs (System Preferences > Sharing > File Sharing, then click the "Options" button, and check the box "Share files and folders using FTP") I now have a drag & drop solution to copying files between computers. Simply drag the file to the Dropzone icon on the dock and then drop it onto one of the many "dropzones" which I have defined, and Dropzone does the rest. Two folders that I added almost immediately? The "Automatically Add to iTunes" folder in the iTunes folder and the Auto Import folder from inside my iPhoto Library (you will have to control-click your iPhoto library and choose "Show Package Contents" to find the "Auto Import" folder).
There are several plugins available to extend Dropzone to other services such as ImageShack, TwitPic, Flickr, and more. For Internet services, not only will the file get copied to where you want it to go, but the URL will be placed on the clipboard so you can paste the URL wherever you want it to go. I often FTP files to my website, and files Dropzone FTPs to a website can also support putting the URL on the clipboard.
There are several other nifty options, Dropzones for starting the screensaver, putting your Mac to sleep, or drag & drop printing a file to the default printer. You can also zip files (or zip and email them) and many other conveniences.
The biggest feature of all was one that I almost overlooked until I watched a screencast from macosxscreencasts.com about Dropzone. A built-in Dropzone called "Install Application" will allow you to drag a .dmg onto Dropzone and have the DMG mounted, the app installed to /Applications, the DMG moved to the recycle bin, and the app launched (it also works with applications which have been .zip'd instead of put into a disk image).
If you are anything like me, the "install a new app" process is several steps that you repeat a lot. Dropzone's handling of it is incredibly fast and works really well. If it opens a DMG it cannot handle (such as an installer), it will simply open the folder. Great, start stuff that saves you time and frustration. Remember how computers were supposed to make our lives easier? Dropzone does just that.