I was at the Hilton on 6th Avenue @ 53rd street this afternoon for a conference. They have a large bag storage operation just off the main lobby (North side) where they will hold bags. It is $3.50 per bag per calendar day. The sign officially says for hotel guests only but I doubt they are really checking most of the time. With the number of folks they were cycling through this afternoon I'm not entirely sure how they could be verifying anything other than the cash changing hands.