Two Systems - One Mouse and One Keyboard

There is cool tool which allows you to use one keyboard and one mouse to access two systems.

Check out the link http://synergy2.sourceforge.net/

synergy: [noun] a mutually advantageous conjunction of distinct elements
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).
Redirecting the mouse and keyboard is as simple as moving the mouse off the edge of your screen. Synergy also merges the clipboards of all the systems into one, allowing cut-and-paste between systems. Furthermore, it synchronizes screen savers so they all start and stop together and, if screen locking is enabled, only one screen requires a password to unlock them all. Learn more about how it works.
Synergy is open source and released under the GNU Public License (GPL).
System Requirements
Microsoft Windows 95, Windows 98, Windows Me (the Windows 95 family)
Microsoft Windows NT, Windows 2000, Windows XP (the Windows NT family)
Mac OS X 10.2 or higher
Unix
X Windows version 11 revision 4 or up
XTEST extension(use "xdpyinfo grep XTEST" to check for XTEST) All systems must support TCP/IP networking.
"Unix" includes Linux, Solaris, Irix and other variants. Synergy has only been extensively tested on Linux and may not work completely or at all on other versions of Unix. Patches are welcome (including patches that package binaries) at the patches page.
The Mac OS X port is incomplete. It does not synchronize the screen saver, only text clipboard data works (i.e. HTML and bitmap data do not work), the cursor won't hide when not on the screen, and there may be problems with mouse wheel acceleration. Other problems should be filed as bugs.