Manual flash shooting for on-the-go, mobile, constantly-changing shooting at events (weddings, reunions, parties, news events,etc.) is not really the smart way to go!!! With "Manual" flash, the flash puts out X amount of popwer, each and every time....meaning the correct f/stop can vary between f/32 to f/1.4...depending on how close or how far the subject is from the flash. When one is, "shooting an event where you're moving around a lot", a MUCH easier solution with the SB 800 flash is the Auto-Aperture method. Pick an f/stop that allows adequate range, and which is pictorially/artistically/practically appropriate for the situation. For example, when you have to shoot "long throws", like to say a podium and you are 45 feet back, set the lens to maybe f/2.8 when indoors. If you are shooting lots of post-wedding reception candids, with groups of 3,4,5,6 people at close range like 15 feet or under, set the lens to f/8 to f/11. Then, set the flash to the Auto-Aperture mode and set the flash to the aperture in use, and it will provide the estimated right amount of flash exposure for the aperture value you have chosen. Pretty simple. The distance range usable for the f/stop in use is displayed on the back of the SB 800.
This can be thought of as "semi-auto" flash control, and is basically the best flash control method that the flash and camera makers could come up with until TTL flash control was invented. And--it works great!