I took an intro workshop on using flash today and realized that my FL-300r wasn't going to cut it, more because of its limited mobility than for lack of power. My instructor recommended getting something with 180 degree swivel in both directions, and a lot of what he showed us involved turning the flash backwards and bouncing off the wall behind. What would you recommend for a relatively compact, relatively inexpensive flash that has swivel? I'm not looking for a lot of power at this point. Ease of use is a plus, obviously, since I'm a novice at flash. Do I need TTL? The Yongnuo III and IV seem popular, but how much of a hassle is it not to have TTL? Any recommendations for a good book on using flash (at more of a "for dummies" level than a "Light and Science" level) would also be welcome. (Yes, I've been looking at the materials on The Strobist site, but wouldn't mind other recommendations for learning material.) I'm using an E-M5 Mark I. Thanks.