Earn 1000 bonus miles when you use mobile check-in this Holiday season on United Airlines

United Airlines is taking a bit of stress off the Holiday travel season with a pretty generous 1000 mile bonus for passengers who use their mobile check-in service.

Mobile check-in is available on all United and United Express operated flights within the United States, Puerto Rico and the U.S. Virgin Islands.

The promotion does have one minor caveat – you need to register at united.com/mobilebonus before your account is eligible to receive the bonus. At that link, simply enter your Mileage Plus number, and the next time you use the United Mobile check-in option at mobile.united.com, you’ll receive 1000 miles (after 6 to 8 weeks).

You can only earn the bonus miles once, and the promotion last until December 31, 2010.

With the United Mobile site, you can check-in, have a mobile boarding pass emailed to your phone, check flight status, view your upcoming flight reservations, check your Mileage Plus account summary and sign up for flight notifications. Their mobile site also lists Red Carpet Club locations and lists Airline contact information.