On Friday, June 6, 2008, the Stapleton Wal-Mart in Denver, Colorado had no tomatoes for sale. No tomatoes in the store.
Today (Saturday) I spoke with Tom, the manager. He explained that they had been advised to pull all tomatoes from the store, and referred me to an 800 number for further explanation.
Google pointed me to the Wal-Mart notice, a salmonella outbreak in Texas and New Mexico (one case in Colorado) and to CDC and FDA notices.
Be careful out there. Wash your produce.
Update: Apparently washing isn't good enough - from a comment elsewhere: There is no bullet proof way to eliminate salmonella from veggies, as with tomatoes for example, the salmonella is not just on the skin and can be washed off, but absorbs into the skin of the veggie and spreads inside the tomato itself.
States with persons with the outbreak strain of Salmonella Saintpaul, by state of residence, April 15 to June 5, 2008.