I downloaded the OAuthDemo Android App from www.marakana.com. It works fine with their included key/secret & callback url. I read up on twitter OAuth API and registere
I had this same problem. I did a packet capture since I knew the URL was good. The response from the server was:
Desktop applications only support the oauth_callback value 'oob'
/oauth/request_token
For me the problem was application type in the Twitter application settings needed to be set to "Browser". Problem was that twitter changed their interface and removed the application type. You need to specify a callback URL in the application settings page to implicitly switch it to Browser type.