*Note: the following does not apply if you only plan to bring a consumer-grade Point & Shoot camera. If you are, take a look at the Canon PowerShot series, which has always given me amazing results. Let me also preface by saying that I am a huge Canon fan and have always packed some form of Canon camera with me on my journeys across the 30 odd countries to date. So what follows would be a Canon-centric list. Nikon users kindly scroll down to the last part of this entry for more info. Alright, onwards with the list of Equipment That Made It All Possible...
1. Canon 350D (RebelXT)
2. Canon 70-200mm f/4 IS L (with hood)
3. Sigma 10-20mm f/4-5.6 (with hood)
4. Canon 1.4x Extender
5. Lowepro Slingshot 300AW camera bag
Camera & Lenses
When taking photos, remember the lens plays a bigger role than the camera itself. So splurge on a good lens, not on a camera. The trusty 350D did really well, and of course the Canon L lens was everything it was hyped up to be. Very easy to handle, has internal zoom, is weather-sealed (thank goodness), and was just light enough to carry even on long hikes during our daily landings. I also brought its non-IS version as a backup, though that one isn't weather-sealed and I was lucky I didn't have to use it.
I brought the Sigma at the recommendation of another traveller who'd taken it to Antarctica as well and I am so, so thankful I did. It does a tremendous job at wide angle shots, which is crucial given the sprawling scenery in Antarctica. You will be very happy that you have a top-notch wide angle lens when you find yourself too close to a stunning iceberg.
A quick note about the hoods that come with the lenses: the L lens' hood was indispensible because you will very likely run into brief spells of bad weather. If you don't want your photos to come out blurry because of water droplets/melted snow on your lens, bring it.
Camera Rental
The Canon and the Sigma lenses cost over $1,000 and $500 respectively, and if you're looking for a cheaper way to use them, I would strongly recommend that you look into http://www.borrowlenses.com . They rent lenses for a tiny fraction of the retail price, and always keep their photography equipment in spanking new condition. Faultless service and quick response time-- these are the guys I trusted to provide me with good lenses for the Antarctica trip, and I can happily say that I am a loyal customer now.
Camera Bag
I knew that a water-proof camera bag was crucial given the weather conditions in the Antarctic Peninsula. Proceeded to rent the Lowepro bag from borrowlenses.com as well, and was so pleased by it that I intend to buy one for myself! Very well designed and compact enough for long hikes.
Miscellaneous
Supporting cast on the trip included the all-important B+W polarizer (67mm for the 70-200) and the Nikon lens pen. I would not travel anywhere without these two items. The polarizer is particularly important in Antarctica because it helps take out the glare of the snow and creates a deeper blue sky.
It goes without saying that backups of key items such as memory cards and batteries are a must. Though I was tempted to bring a back-up camera body after reading a lot online about camera failures on Antarctica trips, I decided against this. As far as I know, none of the 15 or so DSLRs failed on this trip.
For Nikon users, Jerry Fiddler's site has a very extensive Antarctica lens and equipment list.
On Hindsight
If I could do it all over again I would probably bring the 24-105mm f/4 IS L, which has received stellar professional reviews. http://www.the-digital-picture.com is my favourite Canon lens review site.
Alright, that's about it! For convenient referencing, the links are all provided on the menu bar to the right. Hope this helped!