In the latest post to his blog Rob Allen looks at using Vagrant with Zend Framework applications to use for testing your code against multiple ZF versions.
Vagrant is a fantastic tool that enables you to manage and run virtual machines from the command line, including automatic provisioning of them using puppet or chef. The really cool thing about it however from my point of view is that vagrant automatically sets up the VM with a folder called /vagrant that holds the code on your local hard drive from where you started the VM. This means that you can continue to edit your code in your local editor/IDE and test it within the VM easily
Inspired by similar work on the joind.in project, he's created the instructions to make a Vagrantfile that, using VirtualBox and this puppet configuration, sets up and configures a VM you can ssh into and execute your tests.