title: looking to implement a wall (GridView?) that goes off-screen and user can touch to move it around
body: <p><strong>Desired effect</strong>
  I have a bunch of small images that I'd like to show on a "wall" and then let the user fling this wall in any direction and select an image.</p>
  
  <p><strong>Initial Idea</strong>
  as a possible implementation I was thinking a GridView that is larger than the screen can show - but all examples of using this widget indicate that the Gallery doesn't extend beyond the size of the screen.</p>
  
  <p><strong>Question</strong>
  What is the best widget to use to implement the desired effect ?
  A code sample would be especially beneficial.</p>
  
  <p><strong>EDIT...</strong>
  if someone has example code that will let me put about 30 images on a "wall" (table would be good) then I will accept that as the answer. Note that the "wall" should look like it extends beyond the edges of the display and allow a user to use the finger to drag the "wall" up down left right. Dragging should be in "free-form" mode. A single tap on an image selects it and a callback shall be detectable. I have created a bounty for this solution.</p>