Ok, I know they have an audio splitter for headphones, its like a regular one that makes it so youve got 2 ports so you can put 2 headphones instead of just one.

Is there something like that for guitar cables? If so, where should I look to buy one? Maybe Radio Shack or something? Im just looking to hook up 1 guitar and a Mic to my amp, and I know I need the mic-to-guitar cable adapter for this. Any help is greatly appreciated! Thanks~
i'm not sure how good the sound quality would be but couldn't you buy a headphone splitter and then buy two 1/4 to 1/8 adapters and plug them both in?
You're going to run into impedance issues (e.g. volume issues) if you don't use a proper A/B/Y box, but if you're not looking for the most elegant solution then a 1/4" Y-cable is a workable alternative for a lot less.