Everyone love to live out life of a spy and ThinkGeek have such a thing for you like “Uzi Tactical Pen”. This is a unique writing instrument that can double up as a potential life saving tool according to situation. This pen has a DNA Cather which is located on the crown of pen. This DNA catcher is very sharp and can be used to deliver very nasty jab to an attacker that causes only extreme pain and an opportunity to bolt away, while giving you a sample of DNA to use when you go to police.
If you are not anticipating any attack in this situation crown also functions as a glass breaker just in case you are not stuck in your vehicle. It is made out of high-grade aircraft aluminum and it can write upside down and under water. You can get it in $19.99 with 1 year warranty.