If you happen to have a desktop Mac and another portable Mac, Abyssoft’s Teleport might be right for you. The simple application allows you to share your keyboard and mouse across both Macs. As well as, clipboard sharing.
Its easy as pie to set up. Simply download and install Teleport on both the Macs, a few settings later and you’re sailing. The advantage of Teleport is to allow you to manipulate two or more Macs at the same time from one interface, simply by moving off the edge of your screen. The pointer then magically appears on the other Mac’s screen, very much like how it does when your Mac is configured for dual display mode. Only instead of using a single computer and two displays, you are harnessing the power of two computers with a ‘single dual display’.
At the moment Teleport is donationware and works great even with its minor development bugs.
Note, Teleport allows the sharing of Macs but does not function as a Virtual Network Computing (VNC) application because Teleport requires both computers to be present to be able to view what you are manipulating. If you’re keen on carrying out VNC, check out Apple Remote Desktop (ARD), Redstone Software’s OSXvnc or Netopia’s Timbuktu Pro for Mac.