Alternatives to iDisplay

Display management tool

Control your tools with a few keystrokes

Virtual monitor for screen sharing

Second-display utility for iPhone and iPad over USB and Wi-Fi

Turns any device with a web browser into a secondary screen

Monitor resolution and settings manager

Utility to extend trackpad functionality

Add fully customizable extra docks

Add middle click for Trackpad and Magic Mouse

Remote desktop and second display tool

Screen savers

Yet another monitor