Is it possible to use Webform CiviCRM Drupal module to create Stand Alone Forms for gifting a membership to a third party?
Yes, you can do this with Webforms. Create two contacts on the webform. Contact 1 will pay (that's always the case with contact 1), you can set contact 2 to receive the membership. Incidentally you could also add contacts 3, 4, etc. to also receive gift memberships.
More details can be found in these instructions.