mecabq, thanks for answering.
I am not really into city tours - I'd rather go see anything like nature reserve, historic landmarks etc.
Found a tour agent that offers day tours from Riyadh -
http://www.jawlahtours.com/tour_listing.aspx. They list several options of a day tour, wonder which one would be more interesting.
Seen nice reviews for Four Seasons, unfortunately Ritz Carlton is where I will be staying.
AX