Technology side

we thought for a while about the technology part of our project first we were going to just have loads of computers placed around the maze instead from using a satellite navigation system we can have a hand held device that can be carried around by the child and when they get to a trigger point beside the obstacle it will beep and the questions will show on the screen.
There is a link somewhere but i can't find it i will put it up again here are some images instead :D

Here is a sat nav but as our idea is for kids we would change it a bit to look like this . . . .