I downloaded the php wrapper and am having issues modifying the addContact.php....
I basically just need the php code needed to add an email address to list ID 7....
$username = xxx';
$apiKey = 'xxx';
$consumerSecret = 'xxx';
$Datastore = new CTCTDataStore();
$DatastoreUser = $Datastore->lookupUser($username);
$Contact = new Contact();
$Contact->emailAddress = "$email";
$Contact->lists = $lists['lists']->id );
$NewContact = $ConstantContact->addContact($Contact);
the issue has to do with how to set the list to ID 7...
The one piece you're missing is that the lists field in the $Contact object must be an array (since you can have 0 or more lists associated with a Contact). Just change this line line to:
$Contact->lists = array($lists['lists']->id);
That should be the only change you need, the rest of your code looks quite right.