What about Whitby, middle of August? The arcades are a seven year old's dream and if it's sunny you could just sit in the Plough Backyard whilst small child makes friends and plays gameboy (or whatever). The festival atmosphere is all around the town and I'm sure they hold children's events. We went to Bridgnorth one year and they had a load of activities for kids actually on the campsite; things like circus workshops and chalk things. Saddleworth Festival is doing kids things as well. Can't wait to find out what a NYFTE is...especially if it involves a hobby horse.