Update: Thanks for the incredible helpful feedback! I'll definitly report back after the event. perlmonks++

Another Update after the event:
Well, the presentations went quite well. I decided to use the 'peanut-butter and toast'-thing (but as we're in Austria I substituted peanut butter with Nutella (nobody here eats peanut butter...)). We had a lot of fun destroying slices of bread, trying to knock open the Nutella glas, sticking fingers into Nutella, and finally even eating the finished breads.

I had some time left after this so I showed them a small script I wrote some time ago on behalf of my younger son, which calculates the seconds passed since someones birthday. Most kids where around 300.000.000 seconds old.

In some groups there was still time left, so I showed them a text based space invaders clone I wrote some time ago (I didn't showed them the code...).

Over and all it was great fun! Thanks again for the very helpful tips!

EOUPDATE

So, the teachers of my son coaxed me into participating at the 'jobs day' where people present their jobs. As you might have guessed, mine is software developer.

Now I'm looking for ideas on how to introduce 8 year old kids (who don't/barely speak english) to programming. I've got 20 minutes and about 4 kids per shift (from 8:00 until 12:00, I must've been crazy to say yes...)

Here's what I'm currently planning:

• Computer are dumb. The only thing they can do is calculate.
• Programmers have to tell computer what to do.
• Because computers are dumb, this can be quite laborious (as some of you might know...) (even if you're using a swiss army chainsaw)

To show them some actual programming, I thought I'll give them some task they encounter daily (like 'cashier at the supermarket') at let them break it down into 'statements', eg:

start new payment transaction;
while (something is on the conveyer) {
  scan item;
}
tell costumer total price;
take money;
calculate change;
return change;
say goodbye;
[download]

Another idea is to show them some actual, simple code (eg a calculator) and alter it a bit

So, has anybody else an nice ideas or some experiences with little kids and programming?

--
#!/usr/bin/perl
for(ref bless{},just'another'perl'hacker){s-:+-$"-g&&print$_.$/}
[download]