The DiscoDave FAQ:

Who are you?
My real name is David Miller  I live in the wonderfully air-conditioned city of San Francisco with my cat Hardley, who is without a doubt the cutest cat on my bed.
Why are you called Disco Dave?
My loving parents didn’t want to give me an unusual name. Maybe they feared that there would be a stigma associated with an odd name, I don’t know, but after getting letters, bills, phone calls, emails, and so forth for every other David Miller on the planet I would beg to differ. Anyway, my folks gave me the name David Miller; as it turns out, so did quite a few folks of other guys my age. So, when some friends started calling me “Disco Dave” many years ago, I accepted it and soon chose it as my computer email account name. Since then it’s stuck around, and most of my friends call me “Dave”, “Disco”, or “Disco Dave.” Only my parents call me “David.”
 
So does that mean you’re a good dancer?
Uh, no. I dance badly, and I’m not that into disco music either. I used to hate it as a teenager (I was more into punk) but now I can appreciate it for what it is: music crafted with an easy to follow beat, for people who don’t dance very well. I don’t hate it, but it’s not the most interesting stuff in the world for listening; I prefer Bach, Monk, Zappa or almost anything else for that.  But for easy-dancing music, some of that 70’s disco was pretty well made with really high production values.
 
Where did “Disco Dave” come from?
Way back in 1989, my senior year at MIT, I used to hang out with a good friend of mine named Greg S. Greg was a couple years older than me and he had already graduated; he was living off-campus in Somerville with a couple housemates. One of these housemates was this fascinating guy named Elliot H., I’ll never forget him. He was a big thickset black man from Roxbury, while here I was this freaky geekboy from the lily white suburbs of New Jersey. I’d never met anyone like him before; while he was not well educated in a formal sense, he was highly intelligent and well-informed of local and world events. Elliot worked as an armed security guard, he had an impressive gun and knife collection (although he was always extremely careful about handling and storing his weapons), an even more impressive VHS porn collection, and had the uncanny ability to make up nicknames for people that stuck with them. So, there I was, in my senior year at college, hanging out, drinking beer and whatnot with Greg and Elliot, wearing my preposterous Ray-Ban Wayfarers all the time (even indoors). Somewhere around that time Elliot coined the nickname “Disco Dave” for me; I recall him saying I looked kind of like a South American drug lord. (Of course, I wasn’t, but the cheezy Ray-Bans probably were behind his reason.) The name stuck, Greg and my other friends started calling me that, and after I graduated and moved to California, I kept the nickname as a way to avoid the generic “David Miller”.
 
So that’s “Disco Dave”, where did “discodav” come from?
At Stanford, I had to choose a login name for my UNIX account. I didn’t want to be “djmiller”, so I chose “discodave”. However, it turned out that the computer operating system could only accept logins with an 8-character maximum, and d-i-s-c-o-d-a-v-e is 9 characters. So I said, “drop the silent ‘e’” and it became “discodav”. Much, much later, after the advent of the interweb, I wanted to buy the domain name “discodave.com” but it had been taken already by some domain name squatter. Discodav.com was still available, and so I took that. And, in its way, it makes more sense, since for the last 15 years or so I have been “discodav@...”, so it would have been confusing to suddenly change it by adding the silent “e” back.