Check out backgroundrb plugin ( http://backgroundrb.rubyforge.org/ )
This is a plugin that can run ruby code in seperate Threats as so-called "workers", which are basically ruby classes you can run in the background. You can start and access them through backgroundrb's "MiddleMan" fronend object quote: "The MiddleMan front object has a method that takes a class type as a symbol and instantiates a new instance of said class type. Then it returns a job_key to the client(rails). Rails can then call a method on that object through the MiddleMan class."
Then, until you delete the Worker Instance through MiddleMan, this thread keeps running in the background, and you can access it by the worker's unique ID.
As i dont know what exactly you want to achieve, this may be a ver nice solution or overkill.
