I've been curious about this for a while. Every time I drink a bottle-conditioned microbrew, I wonder if the yeast in there is the same yeast used for fermentation, or a secondary yeast (such as the champaign yeasts Vinnie uses for a lot of Russian River brews). Has anyone ever bothered to make a list or some easy way to check if certain brews have viable yeasts to use? I have a friend that has placed gold in quite a few comps by making his recipes stand out with not-so-common yeasts he's found from various micro-brews over the years.
Just a thought.