Moving to Clientside Tech.
The short answer is: Yes, you can use POST as the method of transport rather than GET.
You can NOT use AJAX without Javascript, then you'd jsut have AAX... Asynchronous and XML.... not something that seems useful 😉
There are problems with that document though. While it is an alternative, you can't send anything to the server via POST as he has it set up. Also, there's no interactivity, so if you wanted to have "chats" with the server and client (for things like transparent authentication or things that require more than one round-trip) it can't really be done.
Not to mention, it's still susceptible to the "if Javascript isn't enabled, it won't work" 😉