I was looking this up myself a few days ago for the driveway, I've tried the boiling water trick in the past but honestly it's too much effort and not worth it, I'm going to try what is suggested in this post
http://www.gardenplansireland.com/forum/about146.html
As you can see the salt factor is one to watch out for as nothing will grow in the area after applied, so more suited to areas that you won't want anything to grow.
All we need now is a sunny day......lol