Actually, I've found that Bettys are semi-useful in multi-player games, particularly in a small room and when you have someone chasing you. Drop a whole stream of them in rapid succession (they work best in groups) and the opposing player turns the corner and suddenly finds himself in a betty-storm. Betties also seem to work better when you drop them at high-speeds, then they typically bounce a little higher.Unfortunately, this trick only works a few times, then the other players start to get wise, so you can't use it that often.
I never liked the countermeasures in D3. I really like that Vid of the Smart mine that Atan did tho
It's out back, I'll get you the key...
"Nancy" .... "You may remember her as Audrey Farber, Susan Underhill, ... or how about ... Betty Jo Beolosky." ...