A knife plugin to move a node, or all nodes in a role, to a specific environment
Copy *.rb script from lib/chef/knife to your ~/.chef/plugins/knife directory.
knife-flip is available on rubygems.org - if you have that source in your gemrc, you can simply use:
gem install knife-flip
knife node flip mynode.foo.com myenv [--preview]
will move the node mynode.foo.com into the environment myenv. Passing in the --preview option it will dry-run the flip and show you what cookbooks and versions would be applied if it were actually flipped.
knife role flip MyRole myenv
will move all nodes containing the role MyRole in their runlists into the environment myenv