I have done this when friends travel at hotels where I know they're staying. Best bet is to email the GM first providing them with your direct phone number and asking for some suggestions. Then have about 4 things in mind.
Some of the items I've arranged include:
- wine/chocolate covered strawberries delivered to the room
- a spa treatment at the hotel
- tickets to a special concert/play going on in that city
- a book(picture) about that city
I have found that the hotel has been very accommodating and my friends/family very surprised and pleased when it happens!