SICP free content

I have to recommend the amazing MIT Structure and Interpretation of Computer Programs (SICP) lectures and book.
It gave me a whole new understanding of software and programming.
It continually inspires me.
The ideas have helped me to understand new technologies, languages and frameworks and put them into a larger context.

Just try not to be scared off by the lisp ;)

The book is available for free :
http://mitpress.mit.edu/sicp/full-text/book/book.html

You can even watch the video lectures:
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-001-structure-and-interpretation-of-computer-programs-spring-2005/video-lectures/

Other notes on the course are here:
http://mitpress.mit.edu/sicp/

open source graphic design tools

I recently worked on an iPhone app, and had to do a little bit of graphic design.
I didn't have the money for the adobe suite and needed free/open source versions of photoshop and illustrator, for bitmap and vector graphics respectively.
This two programs are well worth the download:

bitmap : http://www.gimp.org/
The new single window mode makes this app far more usable.

vector : http://inkscape.org/