Disneyland Paris is offering 1 day and 1 night free to guests booking a 3-5 day hotel plus tickets package. The offer is valid for trips prior to April 30, 2010.
The offer can be combined with Disney's Kids Stay & Play Free offers (for under 7s and under 12s) if dates coincide. The hotels the offer can be used in vary over the offer period, and it is not available on certain dates (e.g. around Christmas). Use the calendar on the Disneyland Paris website to check availability.