You don't need a Twitvid account. You can sign in using your Twitter username and password.
You can upload videos up to 2GB large. We have no restriction on the time length of the video.
Since there is no Twitvid account, there is no account to disable.
When you log in, you will see a list of your videos with a delete link underneath each video.
You could use our iphone app (download here), blackberry app (download here), or via MMS/email (details are found here). You could even use TwitVid from popular twitter clients such as Echofon, Twittelator, UberTwitter, Tweetie, Twitterrific, or Twidroid.
Email support@twitvid.com with the URL and name of your application. Your application should be fully functional and integrated with twitvid.