I have Time Warner digital with 2 HD cable/DVR boxes. I hate paying a monthly fee for these. I also have a third TV with no box which only gets the basic 70 or 80 channels. Would TiVo record ALL channels (including those over 100)? If not, would it do so for satellite? I'm looking for a solution that involves a hardware purchase and allows complete DVR-style service (including HD) without rental/DVR fees, if that's possible.
To clarify, I'm under the impression that the cable box itself is what "unlocks" certain premium programming. So, say I buy a TiVo and subscribe, which basically gives me an on-screen program guide and recording capability. Let's say I then call TWC and add some premium channels to my account. Will the TiVo box be able to play those channels??

On a related note, I'm able to find my cable box (which is a hi-def DVR) on eBay. If I simply buy it and hook it up, is it going to work? What can I expect if I do that?

Most cable companies have upgraded their old system of using an A & B box with two sets of coaxial cables to a single coaxial cable system. So would a double jack installed at every tv location in a new house be of any use? When all the tv stations go digital, will the increased bandwith justify the need for two cables once again? Will other new technologies need dual coaxial cables as well (satellite tv, digital cable, fios, etc).

I think it would be cool if Nick Gas would play like four of their shows on Nickelodeon. eg. Double Dare, Legends of the Hidden Temple, Guts, and Wild and Crazy kids. This would give some more variety to Nick and allow kids that don't have digital cable or satellite to watch these shows.