One thing - apart from the cd-copy stuff - that really bugs me in OS-X is the absence of anything even remotely resembling MS-Paint. I suppose most Mac users own some Version of Photoshop or the like but I'm a consultant and developer not an artist that's why I'd like to have something lightweight, easy and free.
After some googling I found
Seashore (probably a little heavy)
let's have a look at them... more to come
P.S.: Drawing could be done with