Now that the New York Times realizes the value of a second monitor, we might as well give them this tip too. Multiplicity is a software-based KVM that allows you to control multiple computers with a single keyboard and mouse. Other similar solutions exist, like Ultramon, MaxiVista and Synergy, but Multiplicity looks the most simple to set up. From the looks of it, configuration is a short process that Multiplicity "wizards" you through. There’s a free trial available, but the software will set you back either $39.95 or $69.95, depending on which version best suits your needs.
A full list of features follows.
Clip and Paste – Share your clipboard contents among your master and slave computers, including images!
File and Directory Copying - Easily move files, or entire directories between computers! (Pro Version)
Hotkey Support – Multiplicity supports fast switching to the connected computers via configurable hotkeys and mouse buttons!
Fade/Darken Indicator – Multiplicity can fade or darken the non-focus computers, to further enhance navigation speed.
Onscreen Display – Multiplicity can be configured to display an onscreen indicator of your current location.
Locking – Support for locking your mouse to a specific desktop (configurable).
Security - Full password protection, and domain control internally.
Threshold Option – Full support for threshold control of mouse movement between machines.
Alternative Control Methods - Multiplicity supports various control methods, such as Jog Dials, and Spatial Controllers!