Plato said "Be kind, for everyone you meet is fighting a hard battle." This is particularly true if you meet someone using a BlackBerry, perhaps the hardest of all battles. But they don't deserve pity. Around BlackBerry users, we must remember manners, courtesy, and a few basic rules of kindness.
Don't be a snob.
Gadget snobbery is never OK. It's ignorant and obnoxious to tell someone they're a bad person because of a phone (unless that phone is a Galaxy Note). Within the rest of the handset nebula, you should let your fellow man stand by his choice.