(I'm trying to figure out exactly what the CableCards are for.) I just bought the Tivo HD and have a question concerning the CableCard. I don't have any 'premium' cable channels - no HBO, Showtime, etc. In fact, the only thing other than basic cable are my HD channels. Do I need the CableCards to get those channels? Comcast is willing to give me 1, but other is an extra $7 per month. I dont know if i actually need them. Everything I read says they are needed for 'premium' channels. Now, if I DO need them, do I need 2? The way I understand it is that you need 2 so you can record two things at the same time. But since I dont really have all the cable extras, do i really need them? Can the unit record one show from the CableCard and the other from the regular channels? Thanks for your help. I look forward to many years of Tivo!