I find ctrl-space, cmd-L and then double-clicking an item brings up the window, pastes, and closes the window again in a reasonably seamless manoeuvre. YMMV, of course.
Heh, I suppose I'm somewhat demanding then, even coming close to the mouse would be a showstopper for me. I used triggers though and got it all working nicely with that, however, it does not paste after being selected. Not even if I double- click the mouse. What happens is that the item gets pushed up to first place in the clipboard, you then manually have to paste it in. And now I have probably spent more time talking about this than I'll ever gain even by having the behaviour I want :)
anyways, despite it's "shortcomings", this is the best clipboard manager I've seen (or rather, best to my tastes)
Andreas