'Virtual Box', and 'Synergy'

Virtual Box

VirtualBox is a general-purpose full virtualizer for x86 hardware. Targeted at server, desktop and embedded use, it is now the only professional-quality virtualization solution that is also Open Source Software.

http://www.virtualbox.org/

Synergy

Synergy lets you easily share a single mouse and keyboard between multiple computers with different operating systems, each with its own display, without special hardware. It's intended for users with multiple computers on their desk since each system uses its own monitor(s).

http://synergy2.sourceforge.net/