External data file for a model

Hello,

I have a number of models that each require some static key/value pairs
to perform calculations. I envision an external file for each model
named the same as the model that the model can open and parse when
needed.

I liken this external file to the .plist files that apple apps have.

Q1. Does this make sense? Is there an easy way to do this?

Q2. Does Rails have a .plist equivalent or something similar?

Q3. Does Rails have built in parsing functionality that can make this
easy (say xml or yaml)?

Many thanks,
Ryan G.