Here’s another example of some interesting set of artwork by Nagai Hideyuki.

More sketches can be found at Nagai Hideyuki’s website

The portrait below is from the Constellation series by artist Kumi Yamashita and was created with a single strand of black thread woven around thousands of small galvanized nails.

More at Kumi Yamashita’s website

I recently came across exploit-exercises.com which hosts Linux virtual servers which contain a number of vulnerabilities and hints on how to exploit them, although I haven’t yet had a chance to try any of them.

From the website:

exploit-exercises.com provides a variety of virtual machines, documentation and challenges that can be used to learn about a variety of computer security issues such as privilege escalation, vulnerability analysis, exploit development, debugging, reverse engineering.

Two photos of the same location outside of Kabul, Afghanistan