One of my past customers had a unique solution: Each version (prod, stage, test, dev) used a different port number, so distinguishing each one was easy. Then I had a little module that altered the site-name variable depending on the port number. It also set a few different things, like enabling Devel on test and dev, and disabling a few things that weren't used there.

Nancy

Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.

I'm administrating a site for which I run several development version:
one private on my laptop, just for me, one also on the same machine as
the production version, for public testing...