The procedurally-generated program is an example of software being written under very tight constraints. It's #1 on the pouet.net 1k chart.

Though if you find that interesting, I recommend looking at some of the other charts. 4k is where things start to get interesting, and it seems as though almost anything can be done in 64k, given enough time and effort. There's even an entire first-person shooter done in 96k!

During my neurosciences courses at Uni, the professors recommended students purchase the Human Brain Coloring Book to help study neuroanatomy. Surprisingly, it proved useful, and has earned a special place on my shelf.

http://www.harpercollins.com/books/9780064603065/The_Human_Brain_Coloring_Book/index.aspx