It sounded like a good idea at the time, I'm sure. You convinced your wife that the two of you should go for a quick roll in the hay. No need for a condom, you think. After all, you've had your laptop on your crotch for at least an hour--you're shooting blanks. (Recently, after a night out drinking your med-student friend Kyle told you that after about 15 minutes your tadpoles were fried from the heat exuded by your laptop. Foolishly, you believed him.)
Your wife says she is tired. You counter with your standard reply. You tell your wife that it'll only take a minute and she won't feel a thing.
Your wife weighs her alternatives. Reluctantly, after realizing that you were being honest; it will only take a minute, she agrees.
The next 75 seconds feel like an eternity of bliss (depending on who you ask.) Three minutes later, you've ridden the roller-coaster of desire and you're on your way to dreamland.
Things proceed normally for about 3 weeks, until you return home from work one day and find the packaging for approximately 289 dollars worth of home pregnancy tests scattered about the kitchen floor. Although you can't quite put your finger on it, something seems amiss. Your wife says not a word. Rather, she takes your hand and leads you to the bathroom where you find what appears to be something resembling the toy chemistry lab you had as a kid.
Soon you realize that your wife has spent the past 3 hours urinating on things. A cold chill creeps up your spine...this time it has nothing to do with getting off.
Eight months later, and the obstetrician's forearm has just disappeared into your wife.
You wake up on the floor. The nurse looks at you with a disapproving glare; "if you can't handle the heat, stay out of the kitchen," she says with her eyes.
Twenty minutes later you've become a father.
So, no, I don't think laptops are an effective alternative to more conventional birth-control options like carrot seeds or jewelry.