I'm building an app where I want to allow users to be able to set up more than one twitter account with my application, so it would be best for me to be able to log them out of twitter before they add a new account so that they can enter their information for their new account and not just be forwarded back to my site because the user already has access with the account that they're logged in with. Others have said that it is not possible to log out a user with the twitter api, but I know that it is because hootsuite.com will log me out of my twitter account whenever I try to add a new one. Thanks!
ANSWERED
I found the solution. You cannot log the user out, but you can force them to log in to authorize your app. You just add the &force_login=true parameter to the end of your authorize url and you're good to go!
http://code.google.com/p/twitter-api/issues/detail?id=469
