title: how to open a new uiview like a popup?
body: <p>i have a tabbar app. there is a button in one of tab.
  i want to open a new uiviewcontroller by animation like popup when i press the button.
  popupviewcontroller has a uiwebview. i want to show some web pages in popup view.
  i designed the popupview in IB.</p>
  
  <p>how can i open my popupviewcontroller with animation like FBConnect.
  FBconnect opens the login dialog view with animation like a popup.</p>