I'll be dropping into Alta this year or next(when I get a pass to the bird) from
the surrounding backcountry, there no law that says you can't snowboard there they just won't let you on the lift. You can drop right into deer valley from the unamed summit right off of Gaurdsmans Pass 30 minute hike from Brighton.
The only problem with dropping in from the surrounding backcountry is that the snow in the surrounding backcountry is probably going to be pristine and rad, while the no snowboarding ski areas will be chopped up, hard pack, and groomed. If I am going for the sweat equity, I'd probably choose quality over making a statement that no one really pays attention too.
Also, rumor has it that this *might* be the last season for the ban at Alta. I've read and heard a few things. Don't be surprised if snowboarding is allowed there this spring and the ban is gone next year. I really didn't seem to think that this was going to happen, but it seems things are rolling this way.