Adding catalog items to cart using web services

While using the webservices, I have been able to create a cart, add an item to the cart, and submit the cart. However, I have not been able to add the user options that might be associated with the item. The web service guide does not really cover this well or at all. Can anyone provide an simple example so I can get a better understanding of syntax if using SOAP and the ServiceCatalogAPI WSDL and the AddItemToCartViaOrder method? Any help would be appreciated.