<pre>
<?php
$proxy = new SoapClient('http://magentohost/api/soap/?wsdl');
$sessionId = $proxy->login('apiUser', 'apiKey');

echo "<pre>";
// Create new attribute
$attributeToCreate = array(
    "attribute_code" => "new_attribute",
    "scope" => "store",
    "frontend_input" => "select",
    "is_unique" => 0,
    "is_required" => 0,
    "is_configurable" => 0,
    "is_searchable" => 0,
    "is_visible_in_advanced_search" => 0,
    "used_in_product_listing" => 0,
    "additional_fields" => array(
        "is_filterable" => 1,
        "is_filterable_in_search" => 1,
        "position" => 1,
        "used_for_sort_by" => 1
    ),
    "frontend_label" => array(
        array(
            "store_id" => 0,
            "label" => "A new attribute"
        )
    )
);

$attributeId = $proxy->call(
    $sessionId,
    "product_attribute.create",
    array(
        $attributeToCreate
    )
);

// Update attribute
$attributeToUpdate = array(
    "scope" => "global",
    "is_unique" => 1,
    "is_required" => 1,
    "is_configurable" => 1,
    "is_searchable" => 1,
    "is_visible_in_advanced_search" => 0,
    "used_in_product_listing" => 0,
    "additional_fields" => array(
        "is_filterable" => 01,
        "is_filterable_in_search" => 0,
        "position" => 2,
        "used_for_sort_by" => 0
    ),
    "frontend_label" => array(
        array(
            "store_id" => 0,
            "label" => "A Test Attribute"
        )
    )
);
$proxy->call(
    $sessionId,
    "product_attribute.update",
    array(
         "new_attribute",
         $attributeToUpdate
    )
);

// Add option
$optionToAdd = array(
    "label" => array(
        array(
            "store_id" => 0,
            "value" => "New Option"
        )
    ),
    "order" => 0,
    "is_default" => 0
);

$proxy->call(
    $sessionId,
    "product_attribute.addOption",
    array(
         $attributeId,
         $optionToAdd
    )
);

// Get info
$resultInfo = $proxy->call(
    $sessionId,
    "product_attribute.info",
    array(
         $attributeId
    )
);
echo "info result:\n";
print_r($resultInfo);

// List options
$resultListOptions = $proxy->call(
    $sessionId,
    "product_attribute.options",
    array(
         $attributeId
    )
);
echo "\n options result:\n";
print_r($resultListOptions);

// Remove option
$result = $proxy->call(
    $sessionId,
    "product_attribute.removeOption",
    array(
         $attributeId,
         $resultInfo['options'][0]['value']
    )
);

// remove attribute
$result = $proxy->call(
    $sessionId,
    "product_attribute.remove",
    array(
         $attributeId
    )
);