Not from internet corsair1447 but i guess social engineering may work.
Try to find out what company's services he uses
Now find out if that company provide some kinda directory service to its users in my case it does so all i have to do is to put is
FIRST NAME =DAVID
LAST NAME =BECKHAM

And i get phone numbers of all david beckham's if it is a user of this perticular mobile comapny.

Or if you know where he/she works/study you can also get a lot of information from there.

In my school for example they keep every students record including address and phone number in a database and every student has a library code corresponding to three enrollment number
if i know some ones library code (which is pretty easy to figure out) i can get all information about them including which books they have reserved and so on.

Hope this helps.