Target Photo, through their Kodak Gallery, offers a free 11 oz photo mug and 20 free 4x6 prints for new members. Shipping is $5.50. Offer must be redeemed within 60 days of the date of your registration.
Note, you get $12.99 towards the cost of the mug. If the mug you pick costs more than $12.99 then you will have to pay the difference.
It seems like you should be able to upgrade your mug to any size using one of these codes: SWEETRETURN, TRYUS4, WELCOME20. Try them and let me know in the comments which code worked for you.