The 'Richard' bit is obvious, but why on earth, I hear reasonable persons asking themselves, the 'ElGuru'?
If my failing memory serves it goes back to my days at RIT in the mid-eighties when I was founding Pres of the Macintosh Users Group (do they even have MUGs nowadays??) and someone (not me) thought the eclectic mix of languages somehow was not entirely inappropriate and coined it and gave it to me as a username for the Vaxen. Then at Cornell the guy who made my business card thought that 'Publications Guru' was an amusing and not entirely inaccurate title, so then the idea just stuck and when I was racking my brain for a domain name to use in addition to 'howlandbolton' it floated mysteriously and majestically before my eyes. I can only hope that in hoc signo non evinco.