This is what all the EyeTV software and El Gato hardware threads here are about, but the answer to your question, since you specifically want to record all encrypted cable channels, unfortunately is no. There's no CableCARD option for OS X and the best that a USB or firewire tuner by El Gato can do is record the unencrypted channels.
There is a relatively new, affordable, and for geeks very exciting, Hauppauge HD PVR device which takes advantage of the analog loophole over component that some Mac users are using to get files (HD to H.264) onto their Macs and the best discussion for it is here, in the non-OS X-specific "HTPC" forum:
http://www.avsforum.com/avs-vb/showthread.php?t=1015617
The device itself doesn't officially support OS X yet--so you use it to get the files, then can process & play those files with software that does run in OS X like VisualHub, Quicktime Pro, Perian, etc...it also doesn't support DD 5.1 just yet, but that's supposedly coming...pay particular attention to the posts in that thread by "ftoak" and "MichaelLAX," who have these things, use Macs and after capture, describe their digitizing and transcoding workflow in detail. Realize this isn't anywhere near as polished a situation yet as EyeTV--this is leading edge stuff and you really, really have to understand what you're doing. (of course, if you're gonna involve your computer in any of this home theater stuff, even EyeTV, that means your IQ has to be above the average home consumer electronics type anyway.)
If your cable STB has an active firewire out, you might try:
http://www.avsforum.com/avs-vb/showthread.php?t=386740
but again, there's a steep learning curve. Good luck...
This is what all the EyeTV software and El Gato hardware threads here are about, but the answer to your question, since you specifically want to record all encrypted cable channels, unfortunately is no. There's no CableCARD option for OS X and the best that a USB or firewire tuner by El Gato can do is record the unencrypted channels.
There is a relatively new, affordable, and for geeks very exciting, Hauppauge HD PVR device which takes advantage of the analog loophole over component that some Mac users are using to get files (HD to H.264) onto their Macs and the best discussion for it is here, in the non-OS X-specific "HTPC" forum:
http://www.avsforum.com/avs-vb/showthread.php?t=1015617
The device itself doesn't officially support OS X yet--so you use it to get the files, then can process & play those files with software that does run in OS X like VisualHub, Quicktime Pro, Perian, etc...it also doesn't support DD 5.1 just yet, but that's supposedly coming...pay particular attention to the posts in that thread by "ftoak" and "MichaelLAX," who have these things, use Macs and after capture, describe their digitizing and transcoding workflow in detail. Realize this isn't anywhere near as polished a situation yet as EyeTV--this is leading edge stuff and you really, really have to understand what you're doing. (of course, if you're gonna involve your computer in any of this home theater stuff, even EyeTV, that means your IQ has to be above the average home consumer electronics type anyway.)
If your cable STB has an active firewire out, you might try:
http://www.avsforum.com/avs-vb/showthread.php?t=386740
but again, there's a steep learning curve. Good luck...