The short answer is that both the Livejournal and the gmail accounts for it were available, so I nabbed it. It wasn't the first "antenna" variant I tried, but it was (oddly) the source of the antenna variations. A long time ago I played an online team FPS in which I went by the handle "antennapedia". It came to mind as a possible nom de guerre to use to keep my fanfiction writing identity separate from my real-life identity. Though many of you know my real name by now, in part because I was a little weirded out by the fandom handle concept.
Why that word, though? I love wordplay of the variety that takes words and slices them up. E.g., I once wrote a usenet post containing the following definitions:
embryoentomologist: one who studies insect pupae
ecoenology: one who studies the effect of Brian Eno on the environment
etymeschatlogy: study of the origin of the word "destiny"
egypteulogist: one who has kind words to say about Egypt
ecclesiepidemiologist: one who studies the spread of religion
endocrepistemologist: one who studies the excretion of knowledge
"Antenna" and "pedia" is such a combination, with the added advantage of being an actual word in biology for a somewhat gruesome mutation of fruitflies. (If you feel courageous, do a google image search on it.)
So, I dunno, I guess it works: it signals my wordnerdiness, and my general scimath geekiness, and it can be shortened.
I will decline to tag anybody, but if you want to, tell us all about your user name.