Relax
Relax was written to solve the repetitive task of setting up the basic infrastructure for REST consumers written in Ruby. When you consider the common elements of most REST consumers (query building, HTTP requests, XML parsing), it becomes fairly obvious that you can DRY things up a lot by extracting out these common tasks into their own library. Throw in a little DSL love, and you have Relax.
Installation
Simply gem install relax or download the gem.
This is still a fairly rough cut, so don't be too surprised if you find it buggy or missing some features.
Getting Started
The files from my presentation at BarCampOrlando are a good place to start. The package includes a PDF of the Keynote, the code examples, the gem, and a README file to get you up and running.
There's also a tutorial in the online documentation that walks you through creating an API with Relax.