I've been using a free little app called Global Hotkey. It gives you some pretty good keyboard shortcut options but works in kind of a strange way. For instance, to make a keyboard shortcut (aka hotkey) for iTunes, you make an alias for itunes, rename the alias to, say, "control f1" and then put the alias in Global Hotkey's Applications folder. It has a Clipboard folder and any text or image put in there will be copied to the clipboard when the designated hotkey is invoked. You'd then be able to do command-v to paste, but that's two steps.

To get it to one step, you could use Global Hotkey's Applescript folder and write a very simple Applescript like Civitan suggests.