Full disclosure: I (heart) guts.
I first saw her work at a craft fair in San Francisco and had a hard time not buying one of everything. Luckily for my wallet, she was out of a lot of shirts in my size (damn you pituitary gland! get to work!). In the end, I only ended up with one lovely item.
Maybe if you all click through to her site and buy something she'll thank me with free shirts? This one is my favorite (hint hint).
I think I can honestly say that I've never before so loved the menstrual cycle. As she says herself on her post (which you should visit), "I know it’s a little crazy-looking, design-wise, but then again, so’s the menstrual cycle."
In this flowchart, I'm digging the style, the color, the craziness and how perfectly she uses the format to make something complicated engaging and fun. I heart it. There should be one on the wall in every high school science class.