I have never had much use for the comma operator in scalar context until I needed to skip the first two lines of file but grab the third.
Normally I would read the leading lines in void context.
my $line = <FILE>;
I have always thought that was really ugly, but now I have something better. The comma operator reads its left argument, throws away the result, then reads its right argument and returns the result.
my $line = ( <FILE>, <FILE>, <FILE> );