Infared emitter for 3.5mm port

Has anyone used a infared emitter that connects to a 3.5mm port [i.e. iPhone4 headset jack] to beam infared signals from the Roomie app to devices?

That concept is almost totally non-functional. There was one product or another doing that at one point and if there are still any in the market, they should be removed in our opinion.

Thank you.