Does it really have to be a ref to be anonymous though? The most common use of anonymous arrays and hashes for me is in return values for subs:

sub foo{
    return { bar => 'baz' };
}
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You could just as easily return an anonymous hash:

sub foo{
    return ( bar => 'baz' );
}
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The other common place to see anonymous hash and array refs (always refs in this case) is in constuction of multi-dimentional data structures:

my $foo = [
    { bar => 'baz' },
];
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So the arrayref isn't anonymous, but the hashref that is the first (and only element) is.

perl -e 'split//,q{john hurl, pest caretaker}and(map{print @_[$_]}(joi
+n(q{},map{sprintf(qq{%010u},$_)}(2**2*307*4993,5*101*641*5261,7*59*79
+*36997,13*17*71*45131,3**2*67*89*167*181))=~/\d{2}/g));'
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