The Year of Living Biblically.
What follows is hilarious, thought-provoking, and ultimately, he finds it's impossible to follow ALL the commandments because of all the contradictions.
Jacobs recuits helpers along the way - talking to rabbis about what a commandment means. The answer is usually, "Rabbis have been debating that for centuries." He visits snake handlers, Red Letter Christians, and Samaritans in Israel. He finds out that you can hire a garment fiber anayzer to ensure you aren't wearing linen/wool combinations.
He also talks about the more personal difficulties he encounters - do you want to sit next to someone who hasn't trimmed their beard in a year - and the ethical conundrums - what does thou shalt not kill mean? Does that mean you shouldn't kill anything, including spiders and ants? Does it mean that you shall not kill, but if someone else does and you reap the rewards, that's okay?
This was a really enjoyable, very funny book. No matter what your religious background or beliefs, he remains respectful and and skeptical (of everything) throughout the whole book. I highly recommend this book for anyone who you know who likes random facts, is interested in history, and any person you have no idea what to get.