A man is walking along a beach in California and comes across a glass bottle sticking out of the sand. As he wipes it off with his shirt a genie bursts from the bottle!
The genie is grateful, kissing the man's feet. "I can't thank you enough for freeing me from my prison! I will grant you one wish, anything you desire!"
The man impulsively blurts out "I want a bridge from here to Hawaii! I'm terrified of flying and would like to be able to drive there!"
The genie frowns. "Seriously? Man, that's gonna be a lot of work. That's thousands of miles, at least. Isn't there anything else you'd like?"
The man thinks harder this time, realizes that his love life has always been a shambles, and says, "I want the ability to understand all women!"
The genie frowns again.
"How many supports do you think that bridge will need?"
I've heard this one told many times with the last line being, "Do you want two lanes or four?"