I've dropped my Blackberry dozens and dozens of times onto concrete, brick, pavement, and even into puddles. Every time it drops, I can't help but wonder if my luck has finally run out and I'll find the device broken beyond repair -- but it always seems to survive. The worst that ever happens is I get a "SIM Card Error" message on the screen, which always goes away when I remove the battery and reseat the SIM card.
Yesterday my BlackBerry took one more step towards total destruction: the screen cracked when the phone fell off my bed onto the concrete basement floor. But the damn thing still works! I'm sure I'll have to be a lot more careful about getting water on the screen though, since any water inside would surely ruin it.
My experience with several different BlackBerry models has proven to me that they are built very well. Ruggedness in any product is a huge factor for me, as I always seem to get things dirty, drop them unexpectedly, or otherwise torture the hell out of them.