A vertical version of the commonly used clock.

Was confused that I didn't see anything close to it on here...

All you need is two repeaters, one redstone torch and six pieces of redstone.
How it works is simple. The torch powers the redstone below it. The repeater at the end of the line powers the block, giving energy to the upper line, going past the second repeater and turning off the Torch, which turns off the lower redstone Wiring, which then unpowers the upper redstone, resulting in the torch turning on again and repeating the process.