Most laptops feature a button to turn off the wireless connection. I find hitting that button has a similar effect, you've just got to restrain yourself from hitting the button again.

My work is writing, so I find it extremely convenient to have internet access as it helps with checking if I've got the meaning correct for words I rarely use in common conversation. It also helps greatly with research, however there comes a time when I have to turn my wireless off and actually use what I've research, etc.