I found the article on configuring Network Address Translation on a stick - http://www.cisco.com/warp/public/556/nat-on-stick.html
Showing that the feature was introduced in 12.1(5)T9. But I'm not seeing it listed in feature navigator to see if, and what, 12.2, etc. releases it is supported on.
If anybody knows, I'd appreciate any info/links that might detail 12.2, etc. releases support it.
Thanks!