From an email I just got. Despite my doubts about 50,000 getting Obama's team's attention, I did what it said so you should too.
It's currently at 41,000, and slowing down. Please take 15 seconds to sign, and a few moments to pass this along to your own networks. To reiterate: this petition has the attention of Obama's team, and they are expected to make their choice public very soon, so there are only a few days left to press for a reform-minded choice.
http://www.fooddemocracynow.org (click on the link to the left)
For a great perspective on this, check out Nicholas Kristof's column, "Secretary of Food," from Wednesdays NYTimes: http://www.nytimes.com/2008/12/11/opinion/11kristof.html