Choskers reply is pretty stupid on 2 counts, but it's great that there are people around who think like that :

Firstly, it is illegal to use the Yellow Pages as an advertising tool for your use, they even place dummy adverts to see if anyone writes to them offering any services, they then prosecute and the fine can be huge.
Secondly, it's just impractical to sit and go through it, it's massive.
With good database software you can import any info you want and let a spreadsheet do the work.