You know when get stuck in a rut teaching the same topic each year, but you only ever seem to teach it one way? I had that with teaching how the internet worked. I reckon it's because by the time the internet pops up in our scheme of work were getting close to the first half term and everyone is knackered, but maybe that's just me. Either way, the teaching I was doing at the time just wasn't up to scratch. So this year I decided to do something a bit different, I introduced a really simple activity that I had thought up on the fly (normally either whilst otherwise engaged or running). We were going to model the internet using chocolate!
Now I don't know what your school's rules on using chocolate for teaching are, but ours is "we don't like it but if they're not bouncing off the walls we can sort of ignore it." I scrapped my original plan to act it out with pupils walking along paths marked by masking tape after a single attempt (too much distraction). Instead we mapped it out on the bench as you can see above. Different chocolate goes in the IP addressed envelopes on the left and the post-its act as the data packets.
Pupils gave their "orders" in the form of plain text (eg mars), they then had to describe the function of every component the "packet" passed through on the way to collecting the chocolate, from the client (cut off in the picture) throught the router and the modem, to the ISP, to the DNS, to the ISP and out to the server (collecting the chocolate), and then back to client. The pupils got it! I was surprised, but I'm really chuffed with them :)