Let's face it - we've all "butt dialed" at some point in time. It's a fact of life and it just happens. I suppose with a BlackBerry it's more of a "butt email" or "butt Tweet" or what have you, but you know how it goes. If you don't remember to lock your device with either the lock button or a password, this can be a major issue for some. I've found many apps that automatically lock my device, but AutoLock seems to work the best for my needs. AutoLock is a simple tool that lets you set a timeout on your device at which point it will lock automatically. You can unlock with the * Send combo or by pressing the lock button itself. You can choose an lock interval from 10 seconds up to 10 minutes and also choose native and third party apps to not allow locking. Overall very cool stuff and a handy tool to have. AutoLock is available for $2.99 in the CrackBerry App Store.
More information/download of AutoLock for BlackBerry