The Flex sockets are so cool, you can connect to any type of TCP/IP server, because of security policy we cant add and change HTTP headers, but using SOCKET you can send any type of HTTP requests and working with responses. So if you hope the task was to implement a download manager with resume download support, SOCKET is a good solution for you.
The same with above, if you want to use printer with air, you can not find any poperties to accessing serial port or usb, but it is possible with a binary socket and serial proxy.
