Disneyland Resort is offering a 4th night free when booking a 3-Night / 4-Day package for arrivals most nights between January 4 and April 11, 2011 with travel completed by April 15, 2011. Bookings must be made by February 19, 2011 and can be made via the Disneyland website.
To qualify, guests must book a 3-night / 4-day package at a Disneyland Resort hotel or a participating Good Neighbor hotel. Disney will then throw in 1 extra night of hotel accommodation.
For full terms and conditions and to check availability, see the Disneyland website.