I love by Blackberry Pearl (8100) but a few things drive me NUTs and make the phone unusable.

Somehow, I keep putting the keyboard in a different mode and I can't figure out how to get it out (buttons are probably getting pressed in my pocket).

- When dialing a number in the phone application, the keypad will only dial letters - you CAN'T DIAL A NUMBER! There is no menu for setting the keyboard mode, so you have to know to hit SHIFT-ALT to turn on Num lock. Type ALT to turn off num lock.
- The phone will get out of multi-tap mode making me type two keys for every letter. To get it back, you have to press and hold the SYM button.

Isn't it ridiculous to not be able to dial NUMBERS on a Phone!??? SO FRUSTRATING!

To make matters worse, the documentation refers to the ALT key, BUT DOESN'T show what key that is! I didn't think my phone HAD an ALT key until I found this PDF with a keypad diagram (the ALT key is the lower-left button, with a arrow up/down on it; the SHIFT key is the 4th button on the bottom, with the ^aA on it).

The 1987 classic (revised Sept 1991) by Theodore T. Tool.

2003 AT&T paper on Master Key vulnerability. Creating master keys (will open any lock in a series, say, an apartment building) is easy given just any normal key and several blanks.

Quoted: In a recent research paper, we describe weaknesses in most master-keyed lock systems, such as those used by offices, schools, and businesses as well as by some residential facilities (particularly apartment complexes, dormitories, and condominiums). These weaknesses allow anyone with access to the key to a single lock to create easily the "master" key that opens every lock in the entire system. Creating such a key requires little skill, leaves behind no evidence, and does not entail engaging in recognizably suspicious behavior. The only materials required are a metal file and a small number of blank keys, which for many locks are readily available.

Learn the details of "bumping" - opening a pin lock by tapping a filed down key blank. The upper pins ballistically fly above the tumbler line, and the lock opens with one tap. Wow.