One or x submissions per form per user

Quick and dirty - make a PHP function to concatenate logged in user email with current date, then set that field to admin only / no duplicates.

add_filter('gform_field_value_user_serial', 'gravity_serial'); 

function gravity_serial() {
  global $current_user;

  if (is_user_logged_in()) {  // Are they logged into WP account?
		foreach($current_user as $key => $value){
      			if($key == 'user_email')
      			$meta_value = $value . date("Y-m-d");
      			}
	 } else {			   // otherwise return error
		$meta_value = 'ERROR';
	}
	return $meta_value;
}

I am not 100% sure about combining the string with a PHP function, but if it doesn't work you can declare a date string and then combine the two strings instead.

Still kinda new to PHP

thanks Scott for the code, however maybe is better and more easy to do with Gravity Forms 1.6, this is a great news Chris! I will wait for the final version public available.

So now the only "problem" is to "assign" the form submission for each single registered user. Any help to deal with this new Gravity Forms version and Wordpress 3.1.2?

Thanks again!