DIY Blood Typing Test

Just in case you've never had your blood typed, or simply don't know, find out whether you're A, B, or O with the DIY Blood Typing Test Kit ($9). The set comes with everything you need to find out what antigens you carry with you in your blood, and even has a laminating sheet so you can carry your results with you — making things much easier on the EMTs if you get into a nasty brawl at your neighborhood bar.