Noun: A folder on your computer dedicated for images taken from the internet and from social media websites like Facebook and Twitter of sexually attractive people for you to pleasure yourself to later.
A lazy, digital replacement for a regular spank bank that consists of images you remember in your head.
Person #1: "Hey dude, what's in that folder on your laptop called White Snake Lullabies?"
Person #2: "It's my spank bank folder man, it has nothing but naked porn stars and my hot Sorority friends in bikinis dude."
Person #1: "Why is it called White Snake Lullabies?"
Person #2: "It's an innuendo dude, I'm not stupid enough to call it Spank Bank."