Here is another complicated "perlish" solution to avoid simple C-style loops as proposed above (and which is the most sensible approach IMHO), this time using closures:

se warnings;
use strict;

sub create_scheduler {
    my $list = shift;
    return sub {
        my $i = shift;
        return () if $i > $#$list - 1 or $i < 0;
        return ( $list->[$i], $list->[$i+1] );
    }
};

my $leg = create_scheduler [ "Chicago", "Saint Looey", "Joplin", "OKC"
+, "Amarillo", "Gallup", "Flagstaff", "Winona", "Kingman", "Barstow", 
+"San Bernandino", "LA" ];
 
my $i = 0;
while( my @pair = $leg->($i++) ) {
    print join( " to ", @pair ), "\n";
}
[download]

You could also "enclose" the index into the closure if you want to create a one-time iterator over your array.