I am in no way asking you to "bite the hand that feeds you," and, to be honest, I never really thought of my question as a way of "ripping off" the ReplayTV and Tivo services. I just thought that maybe I could purchase the DVR and elect not to purchase the advanced features for the monthly cost (essentially using the DVR like a suped up VCR).
Personally, I don't feel like I should have to purchase a monthly subscription to get the advantages the DVR offers over a VCR, but obviously, companies like Tivo and ReplayTV have found a way to force their customers hands by designing products that will not work without the monthly service. In my opinion (from the standpoint of the consumer, of course), this is unbelievably bad business, custmer service, and P/R, but it's obviously making them a lot of money, and that's what counts to the bigwigs in the big offices.
I'll step down off of my soap box now ( this topic has really got me fuming mad at these companies).
Based on the research I've done, it looks like if I can find an older DVR (Tivo series 1, with operating system 1.3 or earlier), I can run it like a normal VCR without a subscription.