I was browsing old websites through Web Archive from 2004 and most of them had the banner that the free hosting provided included in your HTML (beautiful days!). I clicked in some of them and to my surprises, those websites are still working.
One example is this: http://www.freeservers.com
It seems it was stood in time (landing looks from 2006), but it is still working, so I wonder if this one is still a viable bussiness or what...