Though it's actually a little OT, I'll say that I never warmed to the idea of using flash in the corners to bring up ambient. I'm always able to gather enough light to get to where I want to (2-3 stops under) with just available light. I like having the subject pop out a little, but well short of them looking like they're standing in a parking lot at night.
I'd like to use off-camera more during the reception, but I really like being very mobile during this portion of the day so I resist it. It obviously does look nicer, and this is why I work with two flashes (main off-camera and fill on) for the important moments. And I'll do some back lighting of the first dance or general dance floor shots. But other than that, it's on camera bounced off the ceiling with a large bounce card.
And soon to be ETTL with spot metering and exposure lock!
reception! reception! reception!

