Once installed, it's easy to record your 3 minute micro masterpiece. Simply select the QuickCast logo in your toolbar and then click record. You'll get a 5 second count-in and then it's showtime.
Keep an eye on the QuickCast icon, it will indicate how much time you have left. Don't worry about messing up, you can re-record at any moment.
Via Nik Peachey, Yuly Asencion