Syntax for simultaneous "for" loops?

[John Ladasky]

Hi there,

A few weeks ago I was agonizing over choosing a new programming
language, after not having programmed for years.

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=c09b237b.0302060136.5683054e%40posting.google.com

I appear to have chosen Python.  I am really pleased with how quickly
I am getting results.

A few days ago I came across a web page which described a "for"
syntax, which allowed two variables to be stepped at the same time,
through two independent lists.  I said to myself, "that's cool, I
wonder when I might need that?"  Well, I need it now.  But I
bookmarked the relevant web page at work, and we're snowed in here!

Would some kind soul please point me to the relevant information? 
Thanks!

--
John J. Ladasky Jr., Ph.D.
Department of Biology
Johns Hopkins University
Baltimore MD 21218
USA
Earth