Aw !
That would spoil the fun factor for everyone else
But seriously I believe the unit by Antares is OK and TC Electronic make a hugely expensive but effective solution. There are issues using these with vocal monitors confusing the hell out of the singer. There is a thread running on this topic in the LAB Lounge here :-
http://srforums.prosoundweb.com/
Bottom line is I wouldn't shell out all that cash for one.
My 2 cents