Hawke, I believe that Furfly in some way transferred the hosting side to Musea (www.museatech.net). That is my guess as to why openacs.furfly.net is no longer reachable.
There are a few folks who offer OpenACS hosting, including my company, ZillNet (http://www.zill.net/), with monthly prices (currently) at shared server @ $79.95 and your own server @ $175, per month.