Sharing Clipboard between non-networked PC's (KVM style)

Question

My situation is this: I have a PC which is joined to a domain, and another computer 'outside' that network. I'd like to use a KVM style device to switch between them, but sharing the clipboard would be fantastic. When searching for such a thing I found various patents for this type of thing (eg http://www.freepatentsonline.com/6901455.html) but can't see one actually for sale anywhere!

Anyone know of one? Or an alternative suggestion - eg a program that uses USB or another method to connect two PC's and share clipboard without ethernet?

Thanks!