DisplayFusion - DisplayFusion will make your multi-monitor life much easier.
CheatKeys - View Windows keyboard shortcuts in the current application.
WindowGrid - Quickly and easily layout windows on a dynamic grid using just the mouse.
cheat - Cheat allows you to create and view interactive cheatsheets on the command-line.
Mizage Divvy - Divvy is an entirely new way of managing your workspace.
Hotkey Commander - Find out and override what hotkey combination is registered by which application.