When I get people emailing me about a specific theme or layout issue (which has happened a couple of times) it would be great if I could just say "go to the page and on the very, very bottom there's a line that identifies the theme and parameters", then we'd know what they're seeing.

I'm thinking something like:

Layout ID: "lion" for 1200x900 Mac, browser Google Chrome

I think that'd be really useful, and having it be tiny (font-size:8pt) would mean it'd be invisible to people that aren't looking for it.