Ancestry is offering free access to their updated online ships passenger lists and immigration records collection until November 30, 2006. This includes their updated New York passenger lists database from 1820-1957.
Steve Morse has added a OneStep Search Engine for these New York Passenger Lists. This includes
1. Passenger Search
2. Ship Arrival Search (locates the ship arrival in the manifest rolls)
3. Direct access to manifest either by date or by roll and frame