Somehow, I just got around to installing RVM this weekend, and I’m not sure what I was waiting for. Not only does it do the job of allowing you to have easy access to multiple Ruby installations, but it also allows you to save sets of RubyGems as “gemsets”. You can switch to a desired Ruby and a desired gemset all in one command. Very cool. If you haven’t gone to RVM yet (and you’re not on Windows), check it out.