Iphone SDK dismissing Modal ViewControllers on ipad by clicking outside of it

I want to dismiss a FormSheetPresentation modal view controller when the user taps outside the modal view...I have seen a bunch of apps doing this (ebay on ipad for example) but i cant figure out how since the underneath views are disabled from touches when modal views are displayed like this (are they presenting it as a popover perhaps?)...anyone have any suggestions?

I'm a year late, but this is pretty straightforward to do.

Have your modal view controller attach a gesture recognizer to the view's window:

UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapBehind:)];

[recognizer setNumberOfTapsRequired:1];
recognizer.cancelsTouchesInView = NO; //So the user can still interact with controls in the modal view
[self.view.window addGestureRecognizer:recognizer];
[recognizer release];

The handling code:

- (void)handleTapBehind:(UITapGestureRecognizer *)sender
{
    if (sender.state == UIGestureRecognizerStateEnded)
     {
       CGPoint location = [sender locationInView:nil]; //Passing nil gives us coordinates in the window

 //Then we convert the tap's location into the local view's coordinate system, and test to see if it's in or outside. If outside, dismiss the view.

        if (![self.view pointInside:[self.view convertPoint:location fromView:self.view.window] withEvent:nil]) 
        {
           // Remove the recognizer first so it's view.window is valid.
          [self.view.window removeGestureRecognizer:sender];
          [self dismissModalViewControllerAnimated:YES];
        }
     }
}

That's about it. HIG be damned, this is a useful and often intuitive behavior.