Wow thats absolutely amazing! I'm fairly ignorant when it comes to international law, especially Antarctica, but is there any rule against civilians coming down and exploring? I have delusions of a grand pan-global expedition and have been dreaming of making Antarctica a part of it.
The international laws you have to be concerned with are primarily the countries you travel through to get to Antarctica. Technically there is no true laws in Antarctica. To get into the US facilities you have to get permission from the National Science Foundation Site Manager. Usually not too difficult most of the time as long as you arrange it in advance. We give tours to cruise ship visitors during the summer season. As long as it's not during vessel operations it's fairly easy. Vessel operations is a very busy and someone hazardous time but it's generally only a couple of weeks of summer so fairly easy to work around. The cruise lines that go down there know how to make arrangements.
That being said, no one can stop you from just rolling up on the coast in Antarctica but that is a dangerous thing to do in the event you need a rescue team to help you. You want people to know you are there and where you are so they can be thinking about getting you out if needed. For instance, we provide and medevac for a person on a Korean cruise ship during one of my summers.
My last summer I spent 6 weeks at Pole and there was a camp setup about 200yd out from the ceremonial pole. It was setup by a company out of Utah I believe. They would fly people down to visit the South Pole. It is an expensive vacation. They would arrange with the NSF Station Manager to bring visitors into the Amundsen-Scott South Pole Station. You can't just come in if you are not with the USAP. If you did you would be beaten a cuffed. LOL Not really. They would probably just give you a good time to come back for a guided tour. It's all handled basically as a courtesy thing down there.