If I put that code into a separate template, the "heavy lifting" code will have to be moved all the way back up to the top of my application, if I'm planning on using this TT chunk in more than one page. ... so that I don't have to worry that some other part of my app has a conflicting name.

WHen using CGI::Prototype I moved many things into a base class that I wanted to re-use. I had no fears of subroutine name conflicts. My method was simple, but the logic was clear and the results predictable. What exactly are THIS and THAT that they might cause name conflict?