Does anyone know how the DropBox app is able to add a toolbar button to the Finder window? I'm asking because I'd like to do this in some of my apps.
Edit: The dropbox toolbar button is more then a droplet or an app, it gets added to the Finders toolbar buttons list and acts exactly like the other toolbar items. It fades when Finder is inactive(on Snow Leopard) and it has a dropdown menu.
These are called "Droplets;" Amp Up Productivity With OS X Finder Droplets is a pretty good introduction. You may also be able to find some projects on GitHub; jiho/gitx-here is one I found during a cursory search.
[Edit]
I was incorrect! As you pointed out, this is not a Droplet. Judging by some of their bug reports, this is a Finder plugin. There is a surprisingly sparse amount of information on this topic, especially in Snow Leopard. This SO answer may be of interest to you.
