I am a frequent CrackBerry user. That's the slang term for a BlackBerry for those that are not "in the know". In recent months though I've started to look angrily at my CrackBerry. I'm starting to get pain in my thumbs on a pretty regular basis. Any of you that have seen my various computers know that I have an eye to ergonomics. I use a trackball instead of a mouse because it eases my wrists. I have a split keyboard so that I'm more comfortable. I had a mild bout with Carpal Tunnel Syndrome in the early 90's that woke me up to these issues and I've taken them seriously ever since. I've not had any hand pain issues since then, until the BlackBerry entered the scene.
A quick search on Google for blackberry thumb pain results in dozens of articles on the topic. It's obvious that there is a problem here. The thumb wasn't intended to type! I've found recently that even spinning the scroll wheel up and down is a problem. I've resorted to reading the shortcut tips to reduce my keystrokes and simplify things. However, I think the real solution is to just use the thing less.
Thats the rub! The CrackBerry is named that for a reason -- it's addictive. On top of that, people at work have expectations that you have it with you. I'm going to manage it and pay close attention to the pain in my thumbs.