We don't seem to have one of these, and given that this is a gaming forum, It hought it might be rather appropriate.
Every now and then games get discounted to free for a day, week, or however long, on the Apple App Store - In the past id software have made Rage free, EA have made various games free (including Sim City) - they're bargains when you can snap them up. I thought maybe a single place to link these might be a good idea.
Perhaps a good idea would be to ensure you include a link, and the expiry date at which time it goes back to full price.
So to start with one that's free for today.
. Free today only, Monday 11 June 2012.