Alaska Airlines Visa cardholders can earn up to 5000 bonus miles for paying bills automatically with their credit card. The offer is 1250 miles per service company bill (such as cable, phone, etc).
The USAirways Visa has a similar offer of 1000 miles per bill, up to 5000 bonus miles.
Both cards are issued by Bank of America. BofA also issues the Hawaiian Airlines Visa and the America West Visa. If anyone knows whether those cards are offering billpay bonuses, please let me know.
(Hat tip to Free Frequent Flyer Miles.)