The mystery penny item for 5/31-6/1/2009 is
Publix Deluxe Mac & Cheese

Getting this item for a penny requires a $10 purchase and the penny item coupon which you’ll find printed in your local Sunday newspaper*. Many stores will give you the discount without the coupon if you ask for it. You can get as many items for a penny as you have coupons as long as you split your order into $10 increments.

* The Penny Item promotion is not available in Florida.

Curious about what the Penny Item was last week or even last year? Pennywatcher from hotcouponworld.com maintains the Penny Item History Speadsheet that tracks all the Publix Penny Items back to January of 2006.