How to share components between apps

I know you're gonnna say plugins, but bear with me.

I'm a Facebook app developer, and I have an array of different ones
going. I want them all to work off the same basic framework I've
created, but I'm not sure what the best way to do that is. This is what
I want to share:

- various filters in the application controller
- models to store users, etc, complete with the database table
- an entire controller devoted to displaying stats
- various display helpers
- several plugins and config files

I don't know much Ruby metaprogramming, can I accomplish all this with
plugins? Would it be easier to just individually pull all the shared
files from a common repository?

http://rails-engines.org/