Dropbox adds a custom entry in the Mac OS contextual menu, so that if I am in the Dropbox folder and right click on a file or folder, I see a Dropbox entry.
How is it possible to add an entry in the system-wide contextual menu? Are there any hacks? How can I do it programmatically?
If you want to do it just within an App, check out this article from Apple named Displaying a Contextual Menu
But I'm guessing you want to do this for all contextual menus, the bottom of the page I referred you to above talks about how to create a "Contextual Menu Plug-in" (or CFPlugin) installed in a "Library/Contextual Menu Items" directory. Here's the reference guide for plug-ins and CFPlugins. It also mentions you need to implement some Carbon Menu Manager functionality, but I'm not certain if that's appropriate in 10.6 or 10.7.
