Sub InsertSelectedRows()
Application.ScreenUpdating = False
Dim FirstRow&, LastRow&, xRow&
With Selection
FirstRow = .Row
LastRow = .Rows.Count + .Row - 1
End With
For xRow = LastRow To FirstRow Step -1
Rows(xRow + 1).Resize(2).Insert
Next xRow
Application.ScreenUpdating = True
End Sub