Thanks, its getting there :)

my $user           = 'xxxx';
my $password       = 'xxx';
my $signature      = 'xxx';
my $application_id = 'APP-80W284485P519543T';

my $url            = 'https://svcs.sandbox.paypal.com/AdaptivePayments
+/Pay';

my $ua      = LWP::UserAgent->new();
my $headers = HTTP::Headers->new(
        'X-PAYPAL-SECURITY-USERID'    => $user,
        'X-PAYPAL-SECURITY-PASSWORD'  => $password,
        'X-PAYPAL-SECURITY-SIGNATURE' => $signature,
        'X-PAYPAL-APPLICATION-ID'     => $application_id,
        'X-PAYPAL-DEVICE-IPADDRESS'   => $ENV{REMOTE_ADDR},
        'X-PAYPAL-REQUEST-DATA-FORMAT'   => 'JSON',
        'X-PAYPAL-RESPONSE-DATA-FORMAT'   => 'JSON'
        );

  my $json_var = {
        requestEnvelope => { 
          detailLevel => "ReturnAll",
          errorLanguage =>  "en_US",
        },
        actionType => "PAY",
        currencyCode => "USD",
        receiverList => {
           receiver => [
             {
                amount => 5,
                email  => 'andy.newby@gmail.com',
                totalShipping => 10
             },
             {
                amount => 15,
                email  => 'foobar@gmail.com'
             }
           ],  
        },
        returnUrl => 'http://paypal.angelleye.com/paypal/class/1.2/Pay
+_Return.php',
        cancelUrl => 'http://paypal.angelleye.com/paypal/class/1.2/Pay
+_Cancel.php'
  };

  use JSON;
  my $new_json = JSON::to_json($json_var);

#  print "FOO: $new_json \n\n";

my $request  = HTTP::Request->new( 'POST', $url, $headers, $new_json )
+;
my $response = $ua->request( $request );

#print $response->status_line, "\n";
my $json_returned = decode_json($response->decoded_content);

print qq|Location: https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_
+ap-payment&paykey=$json_returned->{payKey} \n\n|;
[download]

The only thing I can't figure out now, is how to get a shipping price in per person. I guess I could just add it into the total cost, but I think people would prefer to see it as a separate field.

Any ideas on that one? (not sure how familiar you are with this payment system)