Hello Does anyone know how you can lock your computer to only use one program temporarily? Strange question - I know. Here's the plan: Im having a little party soon and Im planning on connecting my iMac to some speakers so that my friends can go and choose a song on itunes and add it to party shuffle. The problem is I don't want them to be able to read my emails and play around on my computer. So I was hoping there would be a way to make sure they can only go on itunes. I would be very greatful for any ideas.