#!/usr/bin/perl
use strict;
use warnings;
my @list;
my $index = 0;
while ( <DATA> ) {
    chomp;
    $index++ if /^\s*$/;
    push @{ $list[ $index ] }, (split " ", $_, 2)[1];
}
my @new_list = map { $list[1][$_] . ' ' . $list[0][$_] } 0 .. $#{$list[0]};
__DATA__
Guido bla1 ...
Mike  bla2 ...
Klaus bla3 ...

Guido Meyer
Mike Smith
Klaus Rothschild