{
    local( $| ) = ( 1 );
    print "Press <Enter> or <Return> to continue: ";
    my $resp = <STDIN>;
}
[download]

That isn't quite "any key", but that's what I was going to say also...

print "Press ENTER to continue: ";
<STDIN>;
# continue...
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Update: Thanks to everyone for pointing out my <> v. <STDIN> flaw. When building quick/easy scripts for myself I tend to get lax and use <> when the correct way to reference a line from STDIN is <STDIN>. A bad habit I guess.

No. Never use <> when you mean <STDIN>.

What if you're using the elements of @ARGV to hold keywords or other items?

I'd fail this one in code review, since it has a trivial fix, could cause significantly odd behavior, and indicates a confused mind in general.

My code-review rule is:

if you prompt to STDOUT, you should read from STDIN, not ARGV.

-- Randal L. Schwartz, Perl hacker

Note that getting any key to work is hard to do portably, so I just suggest you avoid the issue. Also <> is not the same as <STDIN> if there is anything in @ARGV.

        - tye (but my friends call me "Tye")

use Term::ReadKey;
ReadMode 4; # Turn off controls keys
while (not defined ($key = ReadKey(-1)) {
    # No key yet
}
print "Got key $key\n";
ReadMode 0; # Reset tty mode before exiting
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system( 'pause' );
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print 'press [Enter] to continue...'; <>;
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Originally posted as a Categorized Answer.

Originally posted as a Categorized Answer.

print "Press Enter to continue ";
<STDIN>;
[download]

Originally posted as a Categorized Answer.

use Term::ReadKey;
ReadMode 4; # Turn off controls keys
while (not defined ($key = ReadKey(-1)) {
    # No key yet
}
print "Get key $key\n";
ReadMode 0; # Reset tty mode before exiting
[download]

Originally posted as a Categorized Answer.