Right before my trip I decided to invest in a Nikon D90. My main body is a D700 which has worked fantastically, namely for the high ISO capability. The D90 has reasonable ISO compared to the D700, but not too close. Why would I buy it then? The video. During the volcano trip I was able to shoot video and shoot photos with no extra wieght; one kit, two completely different tools. While the video that it produces (and the way it produces it) leaves much to be desired, the fact that I can produce video and stills from one package with not weight consequence is amazing, and I will be sure shooting a lot more video now that I have this tool.
Here is a montage of footage from the trip.
For HD, click here (recommended).