Please.... can somebody do the $LJ::READONLY stuff?
The time is fast approaching when we'll need that I haven't had time to start on it. It's not even critical that you get everywhere... the $dbh (master handle) won't have permission to do any writes, so even if the code allows it, it'll just fail. Some of the code will then show the error message, other places will just act like it worked (sadly).
So the important part is that you just insert warnings and messages in the 95% most common places... posting entries and posting comments, mainly. Use the "clientmessage" also to tell people they're in read-only mode. Return error messages on post, so their client doesn't eat their entry, etc.
This shouldn't take long to do and might even be kinda fun?