I usually add a little champagne yeast, but I'm not 100% convinced it's necessary. Can't hurt, I suppose, and that's why I do it. I also don't bother segregating my equipment, but it's a sensible precaution to take.
"I can't believe how many people think Air Lock is pronounced Hydrometer." -BigKahuna
"If you gave me a beer with placenta in it without telling me I would kick you in the nuts." -ODaniel
"We be in a big hurry for dope beer with much alcamahol and flavor, quality, balance, and aroma don't matter. We just wantz to be druck, u know?" -Yooper