If you do much statistics and haven't worked with R, you should try it out. The NY Times profiled the software yesterday:
R is similar to other programming languages, like C, Java and Perl, in that it helps people perform a wide variety of computing tasks by giving them access to various commands. For statisticians, however, R is particularly useful because it contains a number of built-in mechanisms for organizing data, running calculations on the information and creating graphical representations of data sets.
...
What makes R so useful — and helps explain its quick acceptance — is that statisticians, engineers and scientists can improve the software’s code or write variations for specific tasks. Packages written for R add advanced algorithms, colored and textured graphs and mining techniques to dig deeper into databases.
The graphs are pretty, and it's free software. The article describes it as a "lingua franca" for grad students. Maybe not, but I wouldn't invest my time learning anything less powerful.
