If you ever need to perform a reverse phone search, try tracenumber.com. Basically, you type in the phone mumber you want information on, hit submit, and it will come back with all sorts of information on that number. If its a listed number you will get the name and address of the owner, as well as the physical location, phone service provider, etc. The basic lookup is free and if you need to do an advanced lookup they have a paid service for that as well.
In this day and age of harrassing collections agents and fraudulent charity collector, I think its a good idea to know who is calling you. This web site couldbe very useful. And if you have any troubles with prank calls, telemarketers, or hangups, it could be good for that too.