You can change the action associated with the convenience key on the left side of your Blackberry with these simple instructions.
1. Open Options
2. Scroll down to Screen/Keyboard, and click the track ball/pad.
3. Scroll down to Convenience Key Opens, set to Compose here, and click the track ball again.
4. Scroll up or down and select the option you want by clicking the track ball.
5. Press the Escape key, and click Save to save changes.