Hi all. I thought I'd share some code with you:

http://pastie.org/1333848

It's adapted from some code from another post, which I can't find. Sorry to the original author for not linking back to it.

Basically I wrapped up everything you need for a modal picker, like you often see in iPhone apps. Once you include the code, just do something like this:

picker_initialized = false;

my_button.addEventListener('click', function(e) {

  if (!picker_initialized) {
    modalPicker.init();
    picker_initialized = true;
  }

  data = [...some data...];
  modalPicker.show({
    data: data,
    on_select: function(e) {
      var title = modalPicker.picker.getSelectedRow(0).title;

      ... do something ...

      modalPicker.hide();
    }
  });

});

…hope that helps someone.