I'm currently remaking my runaway bot (3rd attempt) in python and use spw param now. Since I used the forum login and cookies in my before tries I always could tell if I was logged in or not.
Using the spw or name/password params I see no direct way of telling that since the page looks like logged out. Of course i can like request http://www.hacker.org/challenge/misc/d/ to tell but a quick html comment in the runaway bot page would be better.