You might remember my blog post on speeding up builds on Travis CI by caching the bundled gems to S3.
This strategy is now even easier thanks to Eric Barendt. He packaged up my scripts as a handy gem: bundle_cache.
In addition to not needing to copy-paste the scripts into your project, I also switched out the dependency on fog to aws-sdk. This reduces the number of dependencies needed on install and thus speeds up builds even further.
As an aside: You should also take a look my hobby project, Piranhas.