rails3 gem: acts_as_something

Question

I'm trying to extract some common code into a gem.

I'm thinking that acts_as_somethingis a good strategy for simple re-use.

Is there a good tutorial that discusses this for rails3 gems? I've found several that discuss rails2 (such as http://guides.rubyonrails.org/plugins.html) but that is specific to rails2

here are some of the tutorials/blogs I've already read:

• http://guides.rubyonrails.org/plugins.html
• http://www.thoughtsincomputation.com/categories/coding-gems-for-rails-3-tutorials (this is an excellent start but doesn't cover the act_as_* issue or controllers)

thanks