Yes. I did it for the 2006 Chicago Marathon. I actually had the 2nd guest's name added to the reservation and remained the primary guest. I used OLCI the day before to lock in a C-level room with my Gold status. Then she went to the lounge (that's where Golds/Diamonds check in at Hilton Chicago), collected the keys, and presented her credit card for payment. She's not a frequent Hilton guest, so she was happy to leave the overall reservation in my name. I got the points, she got the nice room, breakfast in the lounge, and no hassles on the late checkout on race day.