I think he asks to use the RPi within a real machine. And surely it is possible although that would be huge waste of resources, having a whole computer just for mouse and keyboard handling. ;-)
Apart from the software side (taking the source code, stripping all parts unrelated to IKBD emulation), hardware would be trivial, just make something like Jookie's sandwich cable: http://joo.kie.sk/?page_id=417
and you're all set.