It you don't subscribe to Ancestry, and don't want to travel to your nearest public access site, you have an opportunity to search and view all of their worldwide immigration records from now to 25th August 2012. You will need to register and agree to abide by their terms and conditions of service.
The top five databases in Ancestry's Immigration and Travel category are, in order of number of records:
New York Passenger Lists, 1820-1957 - 82,905,466 records
UK Incoming Passenger Lists, 1878-1960 -16,309,783 records
New South Wales, Australia, Unassisted Immigrant Passenger Lists, 1826-1922 - 8,436,409 records
Canadian Passenger Lists, 1865-1935 - 7,286,089 records
Honolulu, Hawaii, Passenger and Crew Lists, 1900-1959 - 6,149,341 records