More info...

UA873 is a new daily service on a 777 starting 6/7/05 (forgot about that one).
UA891 is a 744 until the first week in June when it too switches over to a 777.

Please forgive my statement about the 744 in the previous post... I forgot that they were moving to a twice daily service from LAX. The 777 is much better than the 744, but if you have the miles for an economy standard award then you may as well go for business class....