GoogleGoogle is your best bet for finding local companies. It's as simple as entering the type of product you are looking for along with the zip code (and if you forget to add that to your search, or don't know what it is, Google is smart enough to list those closest to the computer you are using).
You may need to limit your search as I did in the example to the right to eliminate unwanted results. I first searched plastic 17701 and my first set of results listed all of the local plastic surgeons. Not exactly what I had in mind! To eliminate those from my results, I simply used the - in front of words I wanted to exclude, such as surgery and surgeon. This allowed me to see a list of results that is more relevant to what I wanted.