Thanks for the link!

I generated the following class:

//Generated by wsdl2apex

public class StockQuotes {
    public class GetQuote_element {
        public String symbol;
        private String[] symbol_type_info = new String[]{'symbol','http://www.w3.org/2001/XMLSchema','string','0','1','false'};
        private String[] apex_schema_type_info = new String[]{'http://www.webserviceX.NET/','true','false'};
        private String[] field_order_type_info = new String[]{'symbol'};
    }
    public class StockQuoteSoap {
        public String endpoint_x = 'http://www.webservicex.net/stockquote.asmx';
        public Map<String,String> inputHttpHeaders_x;
        public Map<String,String> outputHttpHeaders_x;
        public String clientCertName_x;
        public String clientCert_x;
        public String clientCertPasswd_x;
        public Integer timeout_x;
        private String[] ns_map_type_info = new String[]{'http://www.webserviceX.NET/', 'StockQuotes'};
        public String GetQuote(String symbol) {
            StockQuotes.GetQuote_element request_x = new StockQuotes.GetQuote_element();
            StockQuotes.GetQuoteResponse_element response_x;
            request_x.symbol = symbol;
            Map<String, StockQuotes.GetQuoteResponse_element> response_map_x = new Map<String, StockQuotes.GetQuoteResponse_element>();
            response_map_x.put('response_x', response_x);
            WebServiceCallout.invoke(
              this,
              request_x,
              response_map_x,
              new String[]{endpoint_x,
              'http://www.webserviceX.NET/GetQuote',
              'http://www.webserviceX.NET/',
              'GetQuote',
              'http://www.webserviceX.NET/',
              'GetQuoteResponse',
              'StockQuotes.GetQuoteResponse_element'}
            );
            response_x = response_map_x.get('response_x');
            return response_x.GetQuoteResult;
        }
    }
    public class GetQuoteResponse_element {
        public String GetQuoteResult;
        private String[] GetQuoteResult_type_info = new String[]{'GetQuoteResult','http://www.w3.org/2001/XMLSchema','string','0','1','false'};
        private String[] apex_schema_type_info = new String[]{'http://www.webserviceX.NET/','true','false'};
        private String[] field_order_type_info = new String[]{'GetQuoteResult'};
    }
}

However I have no clue how to use it ...  How can I get the stock quotes in a visualforce page now?