Once you get off the plane in any airport in saudi you may be bombarded with "Taxi!" offers from nationals, which may at first seem like a legitimate service, regulated by the law and local authorities, IT's MOST LIKELY NOT!
Those are usually men and teenagers looking for a quick buck so they go to the airport pickup some visitors and make some money for car maintenance, fun, or a living sometimes
The tricky part here is that they don't have to this for a living, so the possibility of getting a reckless, non-service oriented driver is very high, also extortion is possible, overcharging, dropping you off in the wrong place, smoking and listening to loud music, and many other non-professional habits...
Unique Suggestions: just say no thank you, walk outside the airport and take a registered cab
Fun Alternatives: take a registered cab or SAPTCO bus downtown
During my regular driving short trip from Kobar to Bahrain, I notice large number of Asian workers gathering with their families in the artificial island in the midway between Saudi Arabia and Bahrain.
They seems enjoy the view of being some where out the main land of the Kingdom, have some eats in the fast food restaurants located in this small Islamnd, and take some snap photos by the fountain.
In my opinion, this would perfect tourist trap, and you have to pay SAR 20 to drive half the causeway and to eat fast food.