Chained Near Analysis
This tool will conduct a near analysis that will add a new field for every Near Feature input into the Input Features dataset. Unlike Near, this tool will create a column wise set of Near fields for every Near Feature rather than using the closest of all the near features input into the tool. This results in many more fields, so use this only if you have a specific need to know proximity for every feature within the Input Feature class. Consider a Near Table if you want more detailed proximity information and are comfortable with a higher number of records (many to one).
I largely made this quick script to associate multiple feature classes proximity with the input feature classes very quickly. I usually use long model builder models for this task that are annoying to build. Thought I would share it.