Hi,
you can achieve that by defining a module in your plugin lib directory and then defining mattr_accessors for your configuration values. With that, you are really defining class_level variables (so they will persist during the whole application life) and the corresponding accessors for getting and setting them.
Actually that's my favourite way of defining configuration variables for my plugins, since you can easily provide default values and at the same time anyone using the plugin has a place where to look for the available configuration options.
regards,
Javier
