People have heard me kvetch about Bundler, but some parts of this I agree with a little, and the rest I endorse wholeheartedly.
Do Check Your .rvmrc into Version Control
Your .rvmrc file is an important piece of documentation.
I see too many teams gitignore their .rvmrc file. This is a mistake. For applications, your .rvmrc file is an important piece of documentation. I think this is the best way to communicate the Ruby version dependency to other team members. This is especially true given that an .rvmrc file at the root of your project will make RVM automatically switch to that version of Ruby everytime you change to that project directory.
I recently inherited a project that had a test suite with very little coverage and no documentation as to which version of Ruby was required. I could tell the project wasn’t on Ruby 1.9 yet, so I guessed at Ruby 1.8.7. It wasn’t until much later that I realized Ruby 1.8.6 was actually required. For another legacy project that I worked on, we guessed correctly at Ruby 1.8.7, but it wasn’t until we went to deploy and took a look at the production environment that we realized we should have been developing against Ruby Enterprise Edition (REE) instead of MRI.
Keep your .rvmrc file simple by only specifying the Ruby version...