As Queen said, if you want to do this you'll have to pay for it. It is not something that you can configure on your end ... your ISP assigns IP you an address.
Why do you want to do this? If your router is properly configured, you don't need to have two IP addresses for 99% of the stuff a home user does. Perhaps we can find another solution for you.
I will belabor the obvious here Jipstyle is right. 99.99% of home users do not need a single static public facing IP let alone two. Many businesses get by just fine on one public facing IP (dynamic or static). Uncommon is the company that requires multiple static IP addresses and of these most are on T3 or higher service and have a need for Highly Available Highly Reliable Redundant service, or the business or company has multiple publicly facing web servers in geographically diverse locations such as state or national bank, ISP's, Telecommunications companies, Remote Hosting and the like. If you are planning on starting any of these then yes you will most likely need multiple public facing static IP addresses. For that type of service you would need to get together with your local FCC rep and file the appropiate incorporation forms, apply for business licenses, do your due diligence, file impact statements and other federal documentation.
If on the other hand what you want is to create a simple home network with perhaps a web server thats providing static content updated infrequently while at the same time being able to play online games browse the internet and send a few photos emails or recipes to friends and relatives, then what you need is a cable modem/dsl modem with a dynamic or static IP address (the latter is usually harder to get through most ISP's but if you need one Remote Hosting Sites will offer this type of service and that can be obtained for reasonable prices) and a router. If the cable modem/dsl modem has a wireless or wired switch on the back or a built in router this is all you will need if it has but a single connection you will need to put in a router ( 40.00-180.00 @ newegg for the home network 150.00 - 4000.00+ for the business variety with built in firewall and statefull packet monitoring) and then attach your various pc's laptops and other networkable devices to the router.
The way this works is this: Your ISP delivers content to your home at your request via a cable /dsl/satellite modem which has a unique public facing IP address assigned by the ISP. This can be of the static variety where the ISP gives you a particular IP address and enters your account information in a table next to that IP address and takes it out of their rotation of IP address that they control. Or it can be of the dynamic variety where you "lease" for some contracted period of time (between 24 hours and 7 days) the IP address. At the end of the "lease" agreement this IP address gets renewed or recycled depending on how the ISP designates its routing tables. The cable modem/dsl modem/satellite modem recieves the packets at a particular IP address say 68.124.21.01 then passes the requested packets to the router (internal or external). Each device behind the router (pc's laptops, etc in your house wired or wireless ) has been assigned an internal IP Address depending upon the router modem and configuration using a private range of IP addresses such as 192.168.xxx.xxx. The modem looks at the packet that has been recieved and uses a technology known as NAT or Network Address Translation and rearranges the outer packet layer (think letter envelope) and passes the packet to the appropriate device on the internal network. by doing a "Lookup" of the correct internal address and sending it to 192.168.xxx.xxx
Now I left out a great deal of the actual internal workings lik IP Gateways and Port Forwarding and supplied you with a basic understanding of how an internal network recieves content from other websites. If you have a specific need you can respond to this post or pm me and I will try to answer your specific question.