Did you get this working?
Most likely, your router is using IP 192.168.1.1
And if it's a D-Link or Linksys router, you can log into it, go into advanced settings, change your port mapping so anything arrive on port 80 and 21 (http and ftp) will go to your computer's address of 192.168.1.101.
If you get that set up, then you should be able to get to your computer from the internet using the IP address you see at
http://www.ipaddress.org
Of course, if your router gets a new IP address every time it connects with your ISP, as most do nowadays, the best solution to have an always-accessible connection is to buy a domain name and use something like Deerfield's Dns2Go software, which will keep your changing IP address mapped to your computer.
Given that you have a 3GHz system, the cost of a domain name and single-machine license of Dns2Go should be negligible.
-John