I am a huge, huge fan of the OpenStruct class in Ruby. OpenStruct lets you build data structures that act like classes complete with dot notation. Underlying OpenStruct is really a hash like structure with some semantic niceties that enable the dot methods.
I recently started building a fairly complex structure that represents a blog's metadata and I wanted my keys to be sorted not structured willy nilly. A little bit of thought and looking at the methods that an OpenStruct instance responds to gave me this:
b = OpenStruct.new # complicated routine here that builds the metadata b.to_h.sort.to_h
All this is doing is taking the OpenStruct, converting it to a hash and sorting it and converting it back to a hash – easy peasy!