IR sensors & Arduino--HELP!

I'm planning on using Arduino for IR sensors to communicate with a software that can play movie files. The IR sensors will be used to measure the distance between the viewer and the movie that will be projected on a screen. Depending on the distance of the viewer from the screen, the movie changes.

I'm not program savvy, so I need someone/people to shed some light on this. Has anyone used IR sensors with Arduino? Where can I find helpful resources on the codes?

i think ultrasound is the better way to go. I've seen this live at an exhibition in oslo, and worked pretty sweet.