[Staffslug] input wanted

I'm soon to run a "lunchtime club" at the school which I work at. It's 30 mins or so once a week on practical computing. Would you like to contribute some suggestions? Here's what I plan to do: I certainly will be covering PC architecture (I don't have other hardware like MACs) - Disassembley and reassembly, other physical stuff. Networking too, ending up with 5 machines on a LAN running web servers. I plan to get them to code some simple "hello world" php, then connect to their server and view their pages. Chris.