I don't find them old -- I think they are a cool accessory if you can mix it with the right about of sass and respect for the old school.
I am 31 and have several Pucci pocket squares I inherited from my Grandfather -- I love them. I use them with my blazers and jeans for a pop of color and have simply tucked them hanging out from my back pocket of jeans for something fun.
I don't find them old -- I think they are a cool accessory if you can mix it with the right about of sass and respect for the old school.
^^^I guess I'm hogging them all down here! I see men wearing pocket squares with their suits at least once a day.