I don't know if it's this way in Houghton, but it is in Traverse City, and
since it's the same ISP (Charter), I'd assume it's the same. Charter
blocks incoming traffic on port 80 (the HTTP port), as well as the other
"standard" ports (21, etc). You'll have to set your domain to send traffic
to a different port that Charter isn't blocking (I found that 473 worked),
and then setup port forwarding on your router/firewall, and change the
port Apache is listening on to the appropriate port. If Yahoo! doesn't let
you change the port that traffic is forwarded to, check out
http://www.dyndns.org.