The Entertainment Book CAN save you $, but it depends on the length of your trip and what you plan to do. We (DH + I) saved over $230 on a 16 day trip using the discounts. However, I spent a lot of time making up our daily itinerary and hours on end going over all of the places in the book ahead of time. We used it for many meals and snacks, but also used it for dicounts on dinner shows, and mini golf. Of the 16 days, we were only in WDW parks for 6 days and did a lot of other Orlando area activities on the other 10. At the end of the trip, I tore out all of the national coupons, and left the book w/card on the front seat of the rental car when we returned it at the airport. Hopefully, someone found it, knew what it was, as used some of the remaining offers.
On our upcoming 12 day trip in May 2004, instead of the Entertainment Book, I decided to bid on restaurant.com offers on eBay and have won several. I think the savings will be greater per deal, since there is no wasteful purchase.