What do I need to do?
You just need to download and execute the file. It will check your system for some pre-requisites: NET Framework 3.5 SP1, updated DirectX drivers, Visual C++ 2005 and 2008 Redistributable SP1. These can be found in most recent versions of Windows Vista, but if you don’t have them already they are also provided on installation.
After installing you can jump right into the application or take a look at the settings. You can choose between viewing the Public Timeline, a particular word or hashtag search (e.g.: #followfriday) or your own account. You can also fine tune your render and webcam settings (btw, most people will most likely prefer having the camera on mirror mode).