My parents were awesome enough to get me a microscope when I was a kid, as I was nerdy enough to want one. For fun.
My days of moonlighting as a 10 year old biologist are long over, but, since the thing is still sitting in the closet of my old room, I might as well put it to good use, and what's a better use than beer?
Its a monocular compound microscope, with 3 magnifications (I think 40x, 100x, and 400x, but I can't remember. I'll find out for sure next time I visit my parents).
I'm not sure what type of magnification one needs for yeast, it'd be cool to be able to get viability, or even see what kind of critters I get from wild yeast / bacteria. Could I do anything useful with this?