Being a newbie to C#, I have a question on best practices.

What methodology would you recommend to store local working variable that need to be accessible anywhere in the application? All of these variable are either very slow moving or essentially static but static in that they depend on where the application is being used at (physical location, mobile, desktop, etc...). These variables are determined at start up but typically do not change during usage: but are critical for determining how the app is used and what data is collected (production monitoring system).

I really want this to be a highly streamlined utility that limits its IO as much as possible.

Would you suggest the following (or other)? And why?
Local database?
Static Class?
Registry?