Jangly posted this link on another thread yesterday and it stopped me peeking on Mumsnet this morning so I got 3 hours uninterrupted work done. Am going to turn it on again this afternoon. It's a program blocker, you can turn it on so that you can't access Explorer for as long as you set it for. The only downside is that if you need the www for work you obviously can't access it. But even so, it's good. As it does it program by program, it doesn't block your e-mails. You can block any other program as well. I just felt it was my duty to share it with you all!!!" 
\link{http://www.webjillion.com/archives/2005/08/01/free-software-temptation-blocker/\salvation}