... added to Google's robots.txt. Nothing to see here. Move along.

Yeah, I just noticed this too! google.com/base/s2 just gave me different error messages though then say "s3", though right now I can't reach "s3" at all.

Try... https://www.google.com/base/s2 instead (note the HTTPS).

That gives a familiar error page but the Help and Sign In links point to these internal domains:

Help:
http://jcxx35.prod.google.com:9826/base/help/about.html?hl=en_US

Sign In:
http://jcxx35.prod.google.com:9826/base/welcome

Actually, the standard Google Base error pages link to those domains too...

This is the BASE HREF of the page:

<base href="http :// jcxx35.prod.google.com:9826/base/">

Sloppy code!

Upon further observation, these domains seem to change each time you connect. I've had the following so far:

jcxx35.prod.google.com:9826
jcss13.prod.google.com:9827
jcac63.prod.google.com:9827
jck27.prod.google.com:9829
jcaq66.prod.google.com:9831
jcax36.prod.google.com:9833

And there are probably hundreds more too...

Damn... just realised someone else found a similar thing on Googling Google: http://blogs.zdnet.com/Google/?p=340

I found this url in the code:

http://jcac63.prod.google.com:9827/base/

http://www.google.com/base2 redirects to google.com, for the moment... ;)