Concatenating to Clipboard?

LaunchBar has this functionality, and I use it extensively.

To be honest, I don't use it for pictures, so I don't know how they handle it, but it handles text beautifully.

And the launch key is a double CMD/C (that's hold command and press C twice). Which is intuitive, because it is the same key combination. And next time you just do a normal CMD/C (once) for a normal copy, then we start again.

And what's more, there's clipboard history, so if you forget to double C, you haven't lost anything. And even more… I believe the shortcut access and paste options for the clipboard history is the best I have come across (and I have tried many utilities).

And, (finally), you get the benefits of LaunchBar's main asset as a launcher, which I've become so used to it, I can't live without it.

There are a bunch of utilities that will keep a buffer/queue of the most recently clipped items.

To do the specific function you mention (append to existing item), it would seem fairly trivial to write an app to get the clipboard, save what's there, append the new stuff, then transfer the combined contents back to the clipboard.

A big caveat/gotcha... this would work fairly simply for text, but what about other formats? If there's an image on the clipboard, how would you handle appending text? Or vice versa?

I found one! Lifehacker has featured it, although abet it being only for Windows here it is:

Clipchain