This thread is rather timely seeing as we are really suffering with the noise at our place. Its street noise that is the problem, rather than neighbour-related noise. We are on the 5th floor of an older building so the windows are old and I am not going to pay for double glazing (in fact you would need to completely replace the windows to begin with).
Has anyone ever seen a sound proofing material, that could be attached to windows or to curtains? It doesn't have to be beautiful as we could put it up at night. It would also be good if it had a blackout effect as the street lights are also hard to block!