Last month, TUAW blogger Erica Sadun did a writeup of a preview edition of Avatron's Air Login remote computer access app. Erica and I were both beta testers for the app, which is used to control any number of Macs from your favorite iOS device. Air Login (free, universal) is now live on the App Store.
As Erica noted in her previous writeup, Air Connect (free) is installed on the Macs you wish to control. Those Macs must be running OS X Lion or Mountain Lion. Air Login is loaded on your iOS device(s), and can be used at no cost on your local network to control