how many types of grapes used 4 wine?

[bimmerm5]

I was at work yesterday and a fellow employee and I got into an argument about the # of grapes used to make wines. whyll we both knew that there are thousands of grapes in the world, he said only eighty were used to make wine. Granted, off the top of my head I could only name 20 or 30, I feel there must be far more than 80 used for wine. Even if most are unheard of, and make obscure wines, they are still out there. So any idea of a ballpark # of how many are out there, and please don't say eighty.