I have been doing a lot of work with virtual machines recently. It’s a great way to sidestep machine-specific issues (Windows, I’m looking at you) and set up a consistent development/deployment environment.
However, downloading, installing, updating and setting up each new image has been increasingly tedious. Vagrant looks like a brilliant idea to enable automation of the whole process. I would try this out immediately, except that most of my Ruby development environments are already running inside a Virtualbox VM, and it’s not very likely that one will fit inside another 🙁