DirecTiVo Series 2. The original 40Gig HD was removed and upgraded to a 160Gig drive about 2 years ago.
Powerbook G4 867MHz
Most of the instructions to follow to upgrade HD are in these two threads:
Software for Mac:
Most of the setup is automated, you just have to answer a couple of questions that pop up when you run the setup scripts. I enabled vserver and chose to have it load at bootup. I downloaded TivoTool and it provides a Mac interface to vserver. TivoTool basically does everything on the Mac that TiVoToGo does on Windows. The main difference - you have to hack your TiVo to run it (not that complicated).
As others have stated, I also feel that this is a slap in the face to Mac owners. I can't understand TiVo's mentality on this. It is absurd to think that there is nothing wrong with charging us for something that is freely provided to Windows users. With this mentality, there is no wonder that the hacker community has developed free tools for the TiVo that are actually better than the $69 Roxio program.
TivoTool is awesome. With it, you can rip movies from DVD (encode with mpeg4) and upload them to TiVo, as TivoTool has a "TivoServer" program built in!