It amazes me that anyone considers Barr could ever be a factor.
He's not Perot and he won't get even get a small fraction of the votes Perot did.
If you ask 100 people on the street who Bob Barr is, 99 won't know and 1 won't care.
GM,
The votes the Libertarian candidate will receive this year will largely be from conservatives who cannot stand the dishonest slimebag McCain! So, basically, people don't have to "know" him, other than to know he's not McCain, and represents generally accepted conservative values (McCain doesn't).