Photon has a time out feature that will show a warning message asking you to touch the screen if you have not touched the screen for 15 minutes. (It is something like a screen saver) As long as you touch the screen once every 15 minutes, it will reset the timer and you can use indefinitely.
Unfortunately, it is a necessary feature because without it if someone forgets to turn off photon in flash mode, their iPod will run indefinitely and completely drain their power. Also, in flash mode, the browser is using our server to enable flash. We need to make sure that some one is using the browser and have not forgotten to turn off the browser when not in use.
We are very sorry for the inconvenience. Please note that you can touch the screen once every 15 minutes or less and the session will stay active. (You don't have to wait for the message to show up) Thank you.