Speedometer by Value Apps
Sometimes simple apps that perform a single task can be just what you're looking for. Speedometer for BlackBerry by Value Apps will tell you how fast you are traveling whether by automobile, train, boat or bike - any way that you get from point A to point B. Depending on what you prefer, you can view your speed in miles per hour (MPH) or kilometers per hour (Kmph), and you can set the app to keep your backlight on for continuous monitoring.

You can pick up Speedometer in BlackBerry App World for $3.99 for any BlackBerry smartphone with GPS. On top of this, Value Apps has an awesome contest underway right now for those of you that purchase the Speedometer app. All you have to do to enter is buy the app, leave a comment in App World about Speedometer for BlackBerry, and email Value Apps to let them know you left your comment. The contest runs until the end of November, but I wouldn't wait to enter… especially since the prize is a brand new, unlocked, BlackBerry Bold 9900! You can find out more details at the link below, or at their website.
*Please note, CrackBerry is not affiliated with the contest, we are just helping spread the word. Leaving a comment below is great, but will not enter you in the contest.*
More information/screenshots and purchase Speedometer