I've done this many, many times,...99%, no problem. The only issue sometimes is that the clerk at the desk may want to remove your name and number from the reservation and attempt to replace it with your friends'. This still may happen no matter what you do or who you talk to,...but try this,...

Your best bet is to call the hotel directly after you have made your reservation and request for a Credit Card Authorization to be FAXed to you. Fill out the form and FAX it back to the hotel along with copies of your CC and your driver's license,...front and back of both.

Once FAXed, I would call the hotel back to confirm receipt, and to explain why you are doing this. Keep yourself as THE registered guest,...you are only adding your friend to YOUR existing reservation. Whether you will actually be staying at the hotel or not, be sure to say that you will be arriving much later in the day,...AFTER your friend arrives earlier in the day.

Given my type of work, I would guess I have done this hundreds of times with success,...meaning, points in MY name and account. Just be sure that your name and MR number appears on the reservation before you FAX and before your friend arrives. Also, wouldn't hurt for your friend to also keep a copy of the form you FAX.

Lastly, some clerks *may* not even know what a CC Authorization form is. Don't let them convince you that they don't have such a form. If they don't know about it, ask for a manager. Most higher end hotels, Marriotts, Hiltons, etc,... will have them handy and know the drill. Some hotels on the lower end,...some Choice properties, for example, may not.