Some things you can do:

• Don't have any dynamic pages. Make the entire website static, and just regenerate it on a regular basis, or whenever a new image is uploaded. This has many advantages for the viewers: things can be cached and performance should be better (less strain on the server). It also means you can tar up the site and view locally.
• Install a webserver locally. I fail to see what you need to do to adjust the script to "run locally". It's still run from the webserver.
• Make a crawler than extracts all the pages from the server. You'd have to change all the links and turn them to static pages.

None of this is Perl related. You would face the same problems, with the same solutions, had you written the site using Ada, Haskell or vi-macros.

Abigail