I'm going to jump onto the Template::Toolkit bandwagon. The main package for my most recent web application, called File Exchange System, looks like this:

[...]

use base CGI::Application;

use CGI::Application::Plugin::Session;
use CGI::Application::Plugin::TT;
use CGI::Application::Plugin::Stream qw/stream_file/;
use CGI::Application::Plugin::DBH qw/dbh dbh_config/;

use Template;

[..]
[download]

That gives my CGI::Application application session handling, templating, streaming (for stable file downloads) and intelligent database handle handling.

In addition to using Template Toolkit for web applications, I also use it for the installation script -- I have configuration file templates (for startup.pl, httpd.conf, Log::Log4perl files, and a main configuration file). I use TT to fill in the blanks to create the actual configuration files, then move the completed files to the appropriate locations.

Works great.