Aptonic makes a handy little menubar app called Dropzone 3, which they say will “turbocharge drag-and-drop on your Mac”. I think it was this Lifehacker post which convinced me to buy it, and I’m glad I did.
While the included actions are pretty extensive, much of the beauty of this app is in the extensibility, as you can write your own custom actions in Ruby with the Dropzone Actions API.
- KDiff3.dzbundle: launches my favorite cross-platform diff & merge tool, KDiff3, with the files & folders you drop on it. (Tip: hold down a modifier key like ⌘, ⌥, ⌃, or ⇧ to ‘merge’ instead of ‘diff’.)