Yay, a new toy.
Geekier than normal content follows. Mom, you should skip to the next entry.
What is p0f v2?
P0f v2 is a versatile passive OS fingerprinting tool. P0f can identify the system on machines that connect to your box, machines you connect to, and even machines that merely go thru or near your box.
It looks like it works by using TCP sequence prediction, time-to-live, etc. Playing with fun toys like this is the one thing I miss about working in computer security. It's amazing how much you can learn by induction about the networked world around you just by dumping a few TCP headers. This one's fun, because, unlike, say, nmap, you don't even have to be rude to do your analysis.
As always, remember, it's just a tool -- don't be a dick. In the words of Bill & Ted, "Be excellent to each other!"
Save energy: Drive a smaller shell.