PERSONAL WEB SHARING - ANYONE HELP!!!

Question

My goal is to setup personal web sharing for my mac mini. My intent was to check out my web page design from the internet (just because I could), but now it's changed to wanting to prove that I can conquer this (for my own pride).
Here's my setup: Cable internet (Cox Communications), Airport Express, Mac Mini.
I have put the web page into the /library/webserver/documents folder. I have forwarded port 80 on my router to my local IP address. I don't have my firewall up at this point.
The scenario is as follows: I can access my webpage using my public IP address only on my local area network. If I go to work, I cannot access the page. If I go to my friend's house, I cannot access my page.
I've read countless forums in search of an answer to this dilema. I have talked to Cox about blocking port 80 (which they don't). I have now spent the better part of the day talking to Apple about this problem. They concluded that I was smart enough to set up everything correctly, but were just as stumped as I was in trying to solve the problem.
So, they directed me to this forum. If anyone has any ideas on how to fix this problem, I'm all ears. I'm willing to try pretty much anything to get this to work (my pride depends on it).

Answer 1

I know it may seem like this issue has been answered, but this forum seems to be the closest place for me to report on my very similar situation and see if there is a solution, if not the same one offered by Charlie, above, perhaps some other insight into the nature of this problem, and its resolution.
BACKGROUND and OBJECTIVE:
Like MacDaddy, I am trying to set up a personal web sharer on my iMac G5. I started out yesterday with the goal of setting up an FTP server, because I want others to be able to download very large video files (500 MB to 2 GB). I subscribed to .Mac and I tried this on an iDisk, but I soon learned that the upload times were so "painfully slow," as others have also reported, that I decided to try to let people grab the files directly from my own hard disk. In theory, the Mac is equipped to allow this to occur, right?
I couldn't get the FTP server setup to work, because access was denied, so I decided to shift my effort to creating a personal web server and create pages to files that could be downloaded.
SET-UP:
I use Adelphia Communications as my Internet Service Provider, and I get a dynamic Internet address, which has not changed since I began this process and which, says Adelphia tech support, is not designed to change until and unless I disconnect from their system. I have a small home network, hard-wired and connected through LinkSys BESFR41 router. I created a test home page with a couple of links; the web pages are located in the default ~username/Sites folder.
I know the difference between the 192.168.x.x addresses generated by the router to identify the computers on the network from the 24.49.xxx.xx IP address provided by Adelphia. I learned how to do the port forwarding for the router so that the iMac, which is identified as 192.168.1.102 on the network, should get the HTTP incoming traffic on port 80.
Here is a web page containing links to the screen captures that will illustrate what I've selected in regards to:
• Sharing Preference
• Firewall Preferences
• Router status setup
• Router Port Forwarding setup
http://home.adelphia.net/~jmbattaglia/personalwebsharer/index.html
Also, I understand that the correct format for the URL to be given to my friends goes like this:
http://[IP_address]/~short name of user's account]/
So, this is how I have used it in my situation:
http://24.49.xxx.xx/~JohnMichaeliMacG5/
Also, I've learned that, for one computer on the network to bring up the personal web server pages in its browser, I should use this format:
http://192.168.1.102/~JohnMichaeliMacG5/
where, as I mentioned, the iMac G5 has been assigned the internal network address of 192.168.1.102.
I think I've got everything right, but I'm willing to be corrected in order to get this thing to work properly.
RESULTS:
Like MacDaddy reported, I can successfully access my test web page internally on my private home network. This means that I can access the web page on the iMac G5 when I key in either the 192.168.1.102 format, or when I use the 24.49.xxx.xx format, in a web browser on my PowerMac G4.
Similarly, I can access my test web page when I use the 24.49.xxx.xx format in a web browser on my iMac G5 itself.
However, no one else from the outside world can see my pages! That's the problem which MacDaddy reported, and that's the mystery I cannot understand.
Spurred by the insights of this forum, I contacted Adelphia and I asked them if the HTTP port (80) and the FTP port (21) was blocked. The tech support insisted with absolute certainty that those ports were open and that all ports (up to a very high number) were open. I pushed him hard on it, and he consulted an internal Adelphia document which listed the closed ports, and the ones I am interested in were not closed.
He referred me to Apple, which wanted me to either to upgrade my service warranty contract, or pay $49 to ask a question that they would not guarantee they could answer. I passed on that option, and decided to post my question here, where there may be some resolution on a problem that may be preventing many of us from realizing the full potential of our machines.
SOLUTIONS:
I have not tried to implement the solution that Charlie offered to MacDaddy, which apparently made him a happy camper , because I have no reason to doubt the Adelphia tech support person who resolutely assured me that port 80 is not blocked. If no one can offer any alternative insight into this problem, then perhaps I will have to try Charlie's suggestion out.
But I just thought I'd post my situation, in case someone else can explain what the heck is going on here and suggest an easier fix. It is unfortunate that something which should have taken a few clicks of the mouse to set up has turned out to be a complicated technical adventure over a twisting, winded path lasting over two days, but that's what's happened. Can anybody straighten this path out? Thanks.
jmb
PowerMac G4 Mirrored Doors. iMac G5.   Mac OS X (10.4.6)   2 GB RAM. 2 hard drives. SuperDrive; ComboDrive. LaCie FW DVD. LaCie FW 250GB.