Mine dates back to the earlier internet days about 15 yrs ago when I was trying to come up with a username and each one I came up with was used. so, I figured I'd try zedob because the chances were/are that no-one would have it. Sure enough, I've used it since and have yet to add any trailing numbers.
As for what a zedob is, it's an expression that I heard one of my classmates use in HS down in Loiusiana when she was talking about some guy she met. "He's like "zedob!", eeuwww..." Not a real compliment. Cajun French thing, I guess, but I have never heard it again. It jsut happened to stick in my mind ever since and it's been rather permanent and unmodified ever after.