Personally, I use this to control the media PC in my living room with the keyboard and mouse from my laptop. The screen is my projector. This program allows a laptop to mimic some of the remote keyboard and mouse functionality of a Belkin MediaPilot.

WINDOW MANAGERS
When you press a key or move the mouse, a number of programs can react to or intercept that keystroke. Alt-tab is intercepted by your window manager. Ctrl-Alt-F1 is grabbed by X-Windows. Under normal conditions, neither keystroke makes it to a program like kmclient. Alt-tab, though, is a pretty important keystroke, and using a remote computer without it could be difficult and frustrating.

To prevent your window manager from stealing Alt-Tab (and whatever other keys your session keybindings steals), kmclient can be set to disable your local keybindings. After you exit the program, kmclient will restore your bindings. If this fails, you can try restarting your window manager or your session. Nothing kmclient does should make any permanent changes.

Kmclient knows how to do this with compiz, metacity and sawfish. If you are using GNOME and don't know what window manager you're using, there's a good chance it's one of those. I don't know anybody using KDE, so kmclient does not handle Alt-Tab properly in KDE. Patches to improve that are most welcome.