Combining your request with grep's response, I wonder if you'd want to do something like this:

sub section($&)
{
  my $name = shift;
  my $code = shift;

  use Benchmark;
  my $start = Benchmark->new();
  $code->();
  my $end = Benchmark->new();

  print STDERR "Section $name: ", timestr(timediff($end, $start)), "\n
+";
}
[download]

Then you call it like this:

section A => {
  ... do things ...
};
section B => {
  ...do some other stuff...
}
section C => {
  ...why not more stuff here...
  ...and some more!...
}
[download]

Warning: completely untested ;-)