My own interpretation of an appropriate hardware firewall solution for the home user is the firewall functionality provided in such routers as the Netgear DG834G - I mention this one becuase it's the one I use, but no doubt others on the market also have this functionality.
Businesses and other organisations have security requirements that the home user doesn't - for instance, multiple security domains (one for publicly available Web servers, one for the corporate network); provision of remote access for staff/business partners; and sophisticated "stateful inspection" filtering.
Most home users, I think it's fair to say, have no requirement to allow inbound sessions, and only have the one security domain, as they typically have their web site hosted by their ISP.
So while I imagine that things like Freesco and smoothwall are excellent products and an interesting way of using an old PC (you mean anything these days will work in 8MB?!), I can't help wondering whether home broadband users - at least those with multiple connected PCs - would be better off looking for firewall functionality in an ADSL router.