Shooting with: Digital Rebel XS, EF-S 17-55 f/2.8 IS, Speedlite 430EX II


I'm going to be attending a retirement party for a coworker this week. It's being held in the standard conference room/banquet facility, so the ceilings will be too high to bounce a flash off. So what's the best technique for capturing shots that aren't completely washed out from a direct flash (flash direction, settings, etc.)? It will be similar to a wedding where there's probably some shots from a distance and some close up. I doubt the lighting will be sufficient for shots without flash, and even if they are, it would probably be something like f/2.8, ISO1600 which proves difficult.


ETA: lens