It's easy to think of applications for this technique. Any sort of "plug-in" or "load-on-request" situation. Or "drivers", for instance. Ever use DBI? Notice how you only have to "use DBI;" and then the appropriate "DBD::*" module is loaded according to the datasource in your DBI->connect() call? That magic is done by dynamically loading a module that is contained in, yes, you guessed it, a variable! Actually, the eval method is used there:

# --- load the code
    my $driver_class = "DBD::$driver";
    eval qq{package                     # hide from PAUSE
                DBI::_firesafe;         # just in case
            require $driver_class;      # load the driver
    };
    if ($@) {

#....
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