At this point there's probably nothing in geekdom, no matter how arcane, that hasn't ended up on someone's skin. "In" someone's skin, to be precise. From ASCII art, to xkcd comics, to video games, to binary, to parts of your childhood you just can't leave behind, there are entire sites like Geeky Tattoos now devoted to nerd ink.
RIP Steve Jobs
Internetwork Expert for over 10 years."
Sources: Machine gun Tux: wrightzen; Jobs, left: Cult of Mac; Jobs, right: SODAPOP; RIP toe, Geeky Tattoos; Jobs, arm: Cult of Mac; Stay hungry, wrists: Speak Truth, Breath Love; Stay hungry, arm: Gristle Tattoo; Apple/Jobs icon: gadgetpolice.com; "There is no reason": wease.com; "One more thing": Cult of Mac; Unix commands: Geeky Tattoos; Google It: jessversus; Powered by Google: Geeky Tattoos; Windows XP: traviscostrrr; Windows: bremiclem; Bill Gates: Big Tattoo Planet; RFID: The Loom; Augmented reality: iheartchaos.com; Android: eagyn; Android skateboard: the brand show; HTML body: iamdonte; : interbent; : interbent; CCIE: knuckletattoos.com; Tux: Sabrina Ricci; Debian arm: MicheleM_; Debian back: NiNiaX; QR code: Geeky Tattoos; ShotCode: Ad Lab; Wordpress: Hugo Baeta