On a few of occasions, I've faxed in an advance request for a room upgrade or bump up to the Concierge Floor -- I think the upgrade has been approved in advance most of the time.
As mentioned previously, even if you don't get it, you'll still be able to get lounge access. And, in many hotels, the only things you'd be missing out on would be mouthwash, q-tips, kids sneaking up the stairs to the top floor (I used to be one of them), and a robe.
[This message has been edited by snorkmaster (edited 06-06-2002).]