I've not used mod_perl in an application yet - though I understand it. This is mostly due to the fact that the main service I run on my site is based on code I wrote awhile back that I am not positive would run without consistancy problems mucking everything up. I suppose a simple image-hosting script could be devised well enough to take the mod_perl plunge.

And yes, I do code with use strict; use warnings; use diagnostics; on.

I've wanted to move to mod_perl for two years now, but am apprehensive as it's a major change and the only solid way to know your code will perform reliably in a mod_perl situation is to test it with a lot of active users, which I don't have a way of doing short of putting it on the production server and crossing my fingers. :)