We had about three days straight were our newborn just screamed and screamed and screamed. I was completely exhausted and depressed because I thought to myself, "well, here's *another* colicky one . . ." Then we discovered a trick: we turned the radio on (really loud) tuned to static and sat her in her chair facing a blank wall. She started cooing and smiling and then fell asleep. The only problem was that the static was SO annoying for the rest of us. So (confession time) we just left her there. We strapped her alone in her chair and let her stare at the blank wall. All day.
When I told my mom this she was horrified. But the kid seemed to like it. Crazy chiquita.
(Thankfully for my mom's sake, we found that the trick works almost as well if we put headphones on her. So she isn't *completely* banished anymore.)