For most people the cruise ship approach is the only option unless you have very deep pockets as you mentioned in an earlier post. Some private yachts do go to Antarctica each year, but it's not recommended unless you are exceptionally experienced - and even then you need to be careful!
If you're part of the yachting world or are prepared to become a part of it, this may be an option however.
Cruises vary an awful lot, they're not cheap, but are the cheapest option in terms of time and commitment. Our partner cruise company specializes in matching people to the right cruise. It doesn't have to be wall to wall food, drink, entertainment and lounging about which is what "cruise" so often means to many people, try here
to see what they suggest.
There is always of course the possibility of working in Antarctica, if this interests you, try this page
The tourist and work routes cover pretty much 98%+ of people who go to Antarctica, apart from a few yachtsmen as I mentioned and the odd tale of someone getting a job as crew on a ship from the Falkland Islands, that sums up all the ways I've heard of.
Please let us know if you come up with any other route - Paul