Love the concept and the pitch sold me. Your registration needs some work, there's too many steps/bail out moments. This was the sequence.

  1. Visit http://dragd.is. Big, obvious Register with ___ buttons, excellent.
  2. Click Register with Twitter. Oh, they'll be able to add/remove followers, wasn't expecting that ... alright-ish.
  3. Click authorize. "Your Twitter account was successfully linked to Dragdis. Yey! To finish your registration please enter your email and create a password." Abort!

The point (for me) of registering with Twitter/Google/whatever is to avoid giving yet another site my email address and maintaining yet another password. You already have a shared secret with me (the twitter oauth token), you don't need a password as well. Step 3 should have been "start dragging things".

PS You've almost certainly thought of this, but http://drag.it/ would be a more obvious/memorable URL/brand