What that means, however, is that there needs to be a back end.
Which is not really a problem. A single page that does the server side saving and loading stuff is not a problem.
I still plan on serializing to JSON strings, so that's what'll be posted to the backend.
Now the only snag is some sort of user identification system, and I want this to be as transparent as possible for the casual user(meaning I don't want the user to have to sign up for an account, supply a password, and blah blah blah) because a big "sign up for an account, verify your email, double enter password" should not interfere with a player's experience. He should just be able to call up the page on his computer, and continue where he left off.
But by the same token, I want the user to be able to continue his game on any computer, so the user should be able to modify his/her account and log in/off the system, but joe user should just have a no-frills game account created automagically just by visiting the page.
So, the plan:
I. The user navigates to the page.
II. The script checks for cookies that contain user id and password.
III. If id/pwd found:
A. use xmlhttprequest to validate user.
B. if validated:
1. load game
C. if not validated:
1. indicate error to user
2. create new game
IV. If id/pwd not found
A. xmlhttprequest to create new id/random pwd
B. save id/pwd as cookie
C. create new game
If the player wishes to log in as a different user, there will be a menu item that will take him to a form in which he may do so.