PVR 501 (model=dp501) ( Echostar's Dish Pro 501) - ok. an extraction utility can be found here at Dishrip Yahoo Groups.  You need to sign up for a Yahoo Groups account and then submit a request to Dishrip (the maintainer) for approval to join.  Yes.  I know.  A hassle but once done I was pretty amazed at how well streamlined Yahoo Groups is.  However, the archives are not searchable via google.com :-(    As such, I still prefer the Maillling list structure of the GNU community.  Dishnetwork has also unveiled a new PVR 721(model=dp721?) and it supposedly runs a linux based o/s.  Is it better?  I've heard it is faster and more robust.  But that's it.  As to whether you can log-into it via a bash shell or what-not, I don't know.  It has been on the market from what I hear since July 2002, but I don't see any info about it on dishnetwork.com. For more info on the PVR 721's inards, see http://www.innermatrix.net/forums/showthread.php?s=&threadid=32803 and also search for all posts posted by dmc5439 and omega-EFA (I've found most of these threads deal with illegally hacking the pvr to gain access to channels for which the user neither subscribed or paid for. I neither condone nor do I endorse this type activity.) I've also been advised that the video feeds saved to the hdd on the pvr 721 are triple des encrypted. As to trying to extract those recordings, I am not sure of the legallities. (ie: extracting a free public broadcast that was saved to the pvr 721)