I'm going to Vegas next week I want to take pics of the people I'm with out on the Strip/Freemont street. I've never tried playing with the 2nd curtain yet, but it's my understanding that you can use the longer exposure to get more of the lights, along with the motion of the traffic and then the flash fires at the very end to freeze the subject. Am I right here? I'll be taking: XS, 18-55 IS, 50mm 1.8, and maybe the 75-300- though I don't know what for, along with my new Vivitar DF400MZ. I've been playing around a tad with it and it seems to work fine in ETTL. Any good suggestions for night shots in Vegas?