I'm thinking of writing few blogs on arrays and linked list and for that I need some good drawing tool for drawing images to explain the concept and the logic. I don't want to copy/paste images from other source so if anyone among you knows about any such tool in which I can create images fast and similar to ones given in books and on other site, please let me know.
I believe that Google Docs Draw, could satisfy your needs.
http://googlesystem.blogspot.com/2009/03/drawing-in-google-docs.html