Synergy - Cross-platform software for sharing your mouse and keyboard between multiple computers
SwitchResX - SwitchResX is a tool designed to manage resolutions of all your monitors and HDTVs.
Input Director - Control multiple windows systems with one keyboard/mouse. Share a keyboard and mouse across multiple windows system.
EasyRes - EasyRes is a fast screen resolution switcher for Mac OS X with live animated previews.
Barrier - Barrier is a cross-platform software for sharing your mouse and keyboard between multiple computers...
Resolutionator - Resolutionator makes it simple to use any of your display's available resolutions.