I had a nice set of homemade turn signals on my other bike, but I didn't transfer them to my new bike for a number of reasons: didn't want the extra wiring harness on the new bike (I blame my uber-geekness on the huge wiring harness), the extra weight/size and difficulty in loading the bike on the car bike carrier, and mostly, not convinced that the signals really made any difference (at least during daylight hours). Next fall when my commute happens more in darkness, I may revisit my signals and geek another verison on my bike. If you are interested in my old setup, look here and here.