Topic: breaking capistrano deployment scripts into multiple parts

I have a config/deploy.rb script that I use to deploy multiple websites with extremely minor variations between those different sites. 

Is it possible to break the common portions of those out into an external ruby script and include that script into the deploy.rb file of multiple applications?  This would allow me to maintain a single deployment script (for the most part) and not have duplicate logic shared between the different applications.

Any ideas on how I could accomplish this?