Just wanted to pass along that there is a pretty active group of Industrial Ammonia Operators on LinkedIn. It's got about 1200 members now so it might be worth your while. If you are already a member of Linked-In then do a Groups search for "Ammonia Refrigeration Operators"

If you aren't already familiar with LinkedIn, it's sort of a FaceBook for professionals with over 100 million members in over 200 countries. Primarily it's used for networking but the discussion groups have really taken off.

I still check in here regularly but have found most of my professional contacts are already on LinkedIn.