Those that follow the forums on a regular basis know that I'm absolutely addicted to RIM and their BlackBerry devices.  Throughout my time using them, I've learned random tips and tricks that have made my experience on BlackBerry even better.  With RIM's successful entry into the consumer market as of late, I share them below:

BlackBerry Shortcuts (to display, type them into a message, followed by a space):

• mypin: Displays your BlackBerry PIN.
• mynumber: Displays your telephone number
• myver: Displays the model number of your BlackBerry device, as well as the build number (i.e. 8830/4.5.0.127)
• lt: Current time
  
• ld: Current date

Additionally, navigate to Options -> AutoText.  From there, you can create your own customized shortcuts.

How to tell what technology you/your friend's BlackBerry is using:

• If the device's PIN begins with a "2," it is a GSM BlackBerry
• If the device's PIN begins with a "3," it is a CDMA BlackBerry
• If the device's PIN begins with a "4," it is an iDEN BlackBerry

Note that this applies to the technology that the BlackBerry is intended for (i.e. the BlackBerry Storm 9530 is intended for CDMA use, but if it is unlocked via GSM, the PIN will stay the same).

I'm always open for any tips, tricks, suggestions, and questions relating to BlackBerry devices - feel free to send them over via my Twitter page.