I'd like to be able to detect whether or not a user is accepting cookies, and IF THEY ARE NOT, then be able to revert back to passing their Session ID through the URL.
Is there any way that I can detect whether or not a user is accepting cookies?
Try checking to see if the cookie array exists. This will have a different name depending on what version of php you are using. $HTTP_COOKIE_VARS before ver 4.1.0, and $_COOKIE after.