A new version of the very useful pgfplots package has been released. pgfplots provides a very handy interface on top of pgf/TikZ to generate print-quality plots without too much effort. As many readers will know, pgf works with both DVI and PDF output methods, making pgfplots very handy for generating plots without worrying about other content.
For me, the stand-out new feature in v1.3 of pgfplots is the ability to automatically reverse the axes. As a chemist, I need to do this as convention dictates that some types of data are displayed with the x axis running from high values to low ones. So for me not having to do this by hand is a really significant reason to upgrade. There are lots of other new features as well: I see that the manual now includes a number of 3D surface style graphs, which many people like.
If you are plotting data in TeX, the pgfplots should be very high on your list of packages to consider.