Slang for Cellular Phone or just a Phone.
"Ayo, who was you talkin to on the dialo?"
The equivalent of a typo when dialing a phone number resulting in an unexpected person to answer and an awkward conversation to follow.
Person 1: Dude, this guy called me and I don't know who he is at all.
Person 2: Dude, it must have been a dialo.
Person 1 and Person 2 together: Dude, tubular! *high fives*