I don't quite know what the point is but NTT DoCoMo has a portable Kareoke machine. It's about the size of CD player. It plugs into your phone and your TV and some speakers and a Mic. You have a catalog from which you select songs. They get downloaded over your cellphone to this machine and then played back.
I'm not really sure what the point is. I mean is there really that big of a market for this? I suppose the advantage is that you don't have to go out and by new Kareoke CDs but this was not CD quality. It was crappy midi. Better to just build a webpage with some extention to MP3 to add the lyrics and timing.