open source/free statistical software packages
 

I would like to know if there are any open source (ie free) statistical software packages available. I would like to do some kind of ANOVA analysis... There has been another post (pretty much same question) but without a clear answer....

Cheers

Well, there's pspp which is an open-source alternative to SPSS. Check out www.gnu.org/software/pspp/pspp.html

Undoubtedly, the best open source statistical software is R! It's easy to install and it has very good grafical user interfaces. Also you can download a live CD with R preinstalled.
How to install R and some grafical user interfaces for R (R, JGR and Deducer) in Ubuntu/Linux.
An Ubuntu/Linux live CD with R and some grafical user interfaces for R (R Commander, JGR, Deducer, Rattle, RKWard, RStudio) preinstalled.

gnumeric is capable of ANOVA, and it's pretty much like other spreadsheets you might know, so I recommend it.

I (second) vote for R. I have no idea about any graphical interfaces to it, but having used it command line wise (which is, I assume, how one is supposed to use it?) I can recommend it. Well of course you'll have to know what you're doing, but that's something you have to know anyway, right? :) Plus, the way R works, it's easy to write scripts/programs for/with it, even if it was just one piece of the puzzle.

R has many graphical interfaces. I'm a big fan of RStudio.