The miles are good on any of UAL's partner airlines, tho the in-USA routes are limited.

If you think they are just going to waste, you can also donate them to charities like Make-A-Wish.

If UAL does go under, I'm sure other airlines that take up their routes will honor them - just to lure the passenger base over.

Marguerite in Chicagoland Travel Page: http://mtczajka.net