OK. This made me curious and I had to google for it...
http://www.google.com/#hl=en&q=volleyball+"International+Pursuit+Rulehttp://www.ncaa.org/wps/ncaa?ContentID=18082"...the international pursuit rule was passed as an experimental rule. The rule allows for a ball that has passed completely beyond the centerline outside the antenna to be retrieved if it is returned to that team's playing area outside the antenna."
...and...
http://www.byucougars.com/Filing.jsp?ID=768"The international pursuit rule was also added as an experimental rule for the upcoming season, and can be implemented in a match by agreement of both coaches. The rule allows for a player to retrieve a ball (on second contact) that has crossed the plane of the net to the opponent's free space, provided that player does not touch the opponent's court and sends the ball back to their court, over or outside the antennas, for an opportunity for the third contact."
...and...
http://www.gostanford.com/sports/w-volley/spec-rel/100302aaa.html"Donna (Santa Cruz): I know the international pursuit rule is being used this year in collegiate volleyball. But I don't see a lot of teams running down balls. Why?
John Dunning: (4:37 PM ET ) I think this is a stupid rule. I pray no one gets hurt badly."
FWIW, I saw this done twice this year. Once in a BYU game that I happened to catch on TV and once by an opponent at a UCSC men's game.
John.