I'm thinking of a birthday party for ds, who will be seven, and having found out that all the places he wants to go are booked for months was thinking about having it in our local park (5mins walk from our house). There is a company that sets up a big inflatable slide every weekend that my children love, and he said he could hire it out to me for an hour, which would be cool - it's way too big for our garden, and he wouldn't charge me if it rained (when I'd have to have it at home instead). Am I mad to be thinking about this? Will I lose all the kids (thinking something in the region of 12-15 with four helpers)? I'd love to know if anyone else has done this successfully.