Jessica Hagy might be a bit weird, but she's also extremely funny. Every day, she post an index card on her blog, describing simple situations or life truth with simple charts and graphs. Some index cards are a bit hard to understand if you've never encounter a math or economic book, but most of them are very easy to comprehend, and some are hillarious. Visit her website to make up your mind, and if you like it, check her on amazon, she's having a recollection of her best cards published.

PS : There's even a widget for Mac users, that delivers a new index card to your computer every day.