How Can I Find My Friends E-Mail Address?

I have lost a friends e-mail address , instead of putting in my hotmail contact list straight away ( stupid i know) I put it on a word doc and was going to do it another time, in the mean time my hard drive gave up on me (stupid again as I didnt back up) so I have no way of contacting him as he has moved abroad and he hasnt got my email, does anybody know of a online directory, like a telephone directory but for e-mail address's please, preff 1 you dont have to pay for