A fun and effective way to improve your CW character recognition and gain speed is through the software program called Morse Runner.

Morse Runner is a contest simulator that lets you work a virtual “pile-up” (multiple people calling you at the same time).  You can control the parameters so that your session is as easy or as white-knuckled hectic as you wish.  This program really makes a game out of morse code.  Note: This program assumes that you already know your letters and numbers… it’s not for learning morse code but for helping you to improve your speed.

Download it from the author’s website: http://www.dxatlas.com/morserunner/