I bought the Hauppauge WinTV DCR-2650 Dual Tuner Cable Card TV Tuner from Amazon. The installation was fairly simple although I did have to call Time Warner and work with them for about half an hour to get it registered on their system.
The cable card feature on this allows it to work like the DVR that I rent from Time Warner. I can see the encrypted channels that my Silicon Dust HD HomeRun cannot see. It is not perfect however as many channels are broadcast on an on demand basis, the technology for this is called Switched Digital Video or SDV. SDV is used for the channels that have few viewers, unfortunately for me BBC HD is included in that list. To get the SDV channels your tuner needs to send a signal to Time Warner to send the channel. The Hauppauge cannot send the signal but it does work with a tuning adapter to notify Time Warner that you want to watch an SDV channel.
I picked up a tuning adapter from Time Warner, there was not cost, unfortunately the one I got is not currently supported by Hauppauge so I am still out some channels.
The picture on my HD channels is great, just as good as my DVR if not better. I am really enjoying this new cablecard tuner setup. I do wish that this was a network device like the HD HomeRun so that I could share the tuners on multiple computers. Silicon Dust makes a new version of the HD HomeRun that is cablecard and network capable, the cost has kept me from buying it so far.
More details soon.
