Yes, they're going to be paper wallets, hence the receipt printer.  But how do I script the generation of thousands of wallets?

Hello, I'm planning a science fair which will take place this April.  As one of the exhibits, I'm making a bitcoin dispenser.  Kids will be able to press a button, and a thermal receipt printer will spit out a code for a bitcoin portion.  So far 2000 middle school students are scheduled to come to the fair.

I already have an Epson T20 printer, and a Raspberry Pi to run it.  I'll be making a fancy button in a wooden box, which will connect to the Pi.  I might have to switch to a laptop instead of the Pi though, as the printer drivers are a pain.

The exhibit will also have some posters describing bitcoins, and a presenter to help explain how things work.  I've been running a jalapeno miner the past couple month or so to generate coins for the event, though so far I'm only up to about BTC0.05.  I'm afraid I got into this a little too late.

Could anyone assist me with this endeavour?  Mostly I need to figure out the software side.  What's a good way to dispense bitcoins?  Should I generate a new private address every time the button is pressed?  Or should I simply give them a private link to a webpage where they can get access to the coin?  I'll have to maintain a secure site though.  I'm thinking of printing QR codes, but also including plain text, and a link to more information.

Maybe I could include the current USD value as well, thought they might not be very interested once they learn it's only worth a nickel at the moment.  There's also the question of what to do if the coins are never retrieved.  Kids will be kids, so a good portion of the receipts will probably end up being discarded.  Should I tell them to immediately transfer it to a new account, or else it will be reclaimed in six months?

Any help would be greatly appreciated.
Thanks!
~Rachie