Engine, this is what I've been doing. I'm tracking 10-15 keyphrases that fell spectacularly after Penguin, in the hope of tracking whether my efforts to improve the site are working. That's all I want it for - when my sites are doing well, I don't really care how they're ranking.
Except, what do you mean by "statistical tracking?" I just plonk today's position into a spreadsheet with the date and then go scrolling through to see if it's gone up or down. I wish I knew how to generate charts or something so I could more easily visualize where everything's going.