I just released a small gem called simple_resque which abstracts a pattern that's become very common in my recent projects. I like using Resque as a job queue to move as much work out of the web application as possible. Unlike the usual Resque setup, I never put the workers in the same codebase as the web app. I like to keep the asynchronous parts of the app completely separate from the code that services web requests.
This required some hacking since Resque expects you to pass a Ruby class constant for the worker, but the webapp doesn't have those classes defined. simple_resque provides a thin wrapper over Resque's push method that mimicks the way Resque.enqueue works, but doesn't require you to use a class constant.
For more details check out: https://github.com/subelsky/simple_resque