Try this
vb.net Code:
  1. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  2.         Dim item As Object
  3.         For index As Integer = ListBox1.Items.Count - 1 To 0 Step -1
  4.             If ListBox1.GetSelected(index) = True Then
  5.                 item = ListBox1.Items(index)
  6.                 ListBox2.Items.Add(item.ToString)
  7.                 ListBox1.Items.Remove(item)  'this is optional - you dont have to remove them
  8.             End If
  9.         Next
  10. End Sub