Rinse it off before you cut it, then just shake it off in the sink. For iceberg I guess that wouldn't work, but I don't eat iceberg. I also don't care if the lettuce is completely dry, I like a little moisture on it.
Salad spinner. I do NOT want my dressing watered down, or to have a wet mess on my plate. BTW, leftover lettuce that you have spun dry, but NOT put dressing on, keeps better than wet lettuce. Put it in a zipbag with a square of paper towel.