Verb, meaning to completely dominate something. Comes from the card game Bridge, where the best strategy that ever was is named Bitchkilla 3.0.
The full name of the strategy, however, is inappropriate in mixed company, therefore, the term '3.0' was born.
Same as pwned.
"Dude, you just got 3.0'd!"
or "Ok, time to 3.0 these suckers."