I think a pretty nice use of our is to localize $_. So, for example, with List::MoreUtil you can write code like this:

my $first_stuff = first_value {$_ > 2} 1..10;
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and here is the code that does the magic:

sub first_value (&@)
{
    my $test = shift;
    local $_;
    foreach (@_)
    {
        return $_ if $test->();
    }
    return undef;
}
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Notice, how you localize the elements of the array one by one, so that you can refer to them as $_ in your code.

I do not really know, how could you achieve similar effects without using our, if you can at all, but I am not entirely sure...