Tim Hortons is offering their US Facebook fans coupons good for a free donut with any purchase valid only on June 7, which is National Donut Day.
You need to "like" the Tim Hortons' US Facebook page to get the coupon, which you can find here. The deal is similar to one by Krispy Kreme, except the Krispy Kreme deal requires neither a coupon nor a purchase.
Tim Hortons is also offering two new, limited-time Timbits donut hole flavors this summer: Orange Tangerine and Caramel Glazed. They're offered in a 10-pack for $1.99.