We had one last year and made just over $500 Every year we get together with all our neighbours and have one massive garage sale on our street. We haven't had one yet this year but I have been putting things aside to sell (toys, books, videos, kitchen stuff).
My dad is selling his house and moving into a 2 bedroom apartment. He is going to have a garage sale later this month and I told him I would help. He has lots of 'treasures' to sell.