I'm in danger of being redundant, since I've mentioned this software package FOUR separate times over the past couple years: here and here in 2007, briefly in 2008, and again this past summer. But I've used the software regularly since 2005 for data analysis and presentation material. I really like it.
Anyway, I wanted to give props to SAS for the latest version of JMP. There are a few big things they added (I liked the animated graphs) and several smaller additions, but the best feature for me has been the graph builder. In the past when I was trying to see a trend in data I would graph some things as linear plots, try them as contour plots, maybe add histograms. In other words, I would play around with it.
Graph builder sort of automates that process. You can interactively add data to the x-axis, multiple sets of data to the y-axis, separate plots with the same x-axis, separate sets of data on the same plot, etc. If you don't like what you see, remove a set of data, or graph it differently. It's helped me out with two specific problems already, which makes it worthwhile in time savings alone.
I don't work for SAS, I don't get any compensation from them. I just really like the software.