One is to fill out all the forms and drop them into the mail-box at USA consulate which including the return mail envelope. The other is to fill out all the forms and make a appoitment for an interview. The disadvantage of the first one is not safe. Because you have to put your passport and LP into the envelope and they will return them with the VISA by mail.
Anyway, my friends did it that way three weeks ago in Toronto. They got five years VISA.