Did you know you can put coderefs in @INC?

#!/usr/bin/perl -wl
BEGIN {
    unshift @INC, \&magic_inc;
    sub magic_inc {
        print $_[1];
        my $i;
        return \&magic_load if $_[1] eq "Foo/Bar.pm";
    }

    my @src = ("print q(Foo::Bar loaded!);", "1;");
    sub magic_load {
        return defined($_ = shift @src);
    }

}

use strict;
use Data::Dumper;
use Foo::Bar;
[download]

The interface is somewhat obscure, but this close to the guts, you have to expect it.

Makeshifts last the longest.