To start with this is not a "real" static IP but it can act like one. You will have the same IP every time you sign on to your Internet Service Provider (ISP). If someone already is using the IP you want your ISP will just hang up. This can be prevented from the ISP and the Admin could know about it but I have not found a place that is hasn't worked on.
This is important if you have a FirstClass, Telefinder, NovaServer BBS or FTP on your computer. So that people can sign on to the same IP every time.
Included are simple instructions and the extra stuff for your mac to have a free static IP.