I had that installed but it wasn't working. I think I fianlly figured out why it wasn't working. I am going to give it a few days, and see if I can come up with some stats.
I have done a lot of searching on this topic also, and have found the following sites that track both natural and PPC keywords:
www.adwatcher.com,
www.benchmarktracking.com and
www.webmetrics.com. These were the best that I found, and it said that it could track msn, yahoo, and google. That would be nice, because they could all be tracked together. Thanks for your help!