What is best way to get the phone number of an old friend who lives in the Greater Houston area?

I have been trying to obtain the ohone number of an old friend who lives in the Greater Houston area (Zip Code 77007) and with whom I went to undergraduate college and interested in touching base. I have his full name, his full street address, and area code. But he is not in the white pages and he is retired. I tried various avenues and not been successful. Also, I am suspcious of the pay a feee for a phone number and other personal information web sites, which all seems a bit dodgy to me. Is there any other ways I can try find it. Or should I just send him a short letter given all the time I have so far wasted?