There is a register rewards offer available at Walgreens through 11/28:
Save up to $4.00 POST Cereal and POST Pebbles Treats YourBucks® Offer in future savings when you buy five or more POST Cereal and POST Pebbles Treats
This offer is advertised on the Coupon Network. You can use this offer to get Great Garins cereal for 75¢ per box
Buy four Post Great Grains Cereal, 13 oz $2.50 each
Use 4 $1/1 Post Great grain cereal printable coupons (will need access to two computers)
Pay $6 and get back a $3 Register Rewards
UPDATE: It looks like you can only print one coupon per computer.
Thanks, Wild for Wags!