I also used my 'usual' online presence username which is the same one as on here: Lilliaceae
I would definitely recommend creating an unique name rather than using your real name though, for the already mentioned reasons, but I see how hard that might be...
Some ideas for a truly unique username:
• take any peculiar words that aren't in the day to day vocabulary, but sound cool (and maybe even have a cool meaning) any dictionary might help.
• think of something you like and translate it into another, preferably uncommon, language (Latin, Ancient Greek). For myself, I just took the Latin name for a plant family, the Lily, and sort of made it my own (it's technically 'liliaceae' in Latin, but I added an L)
• Give a 'common' username a unique spelling (e.g. like Mystic7)
• Try an anagram of your name, the name of your city, your sibling, whatever (I know weird example but: Tom Marvolo Riddle turns into 'I am Lord Voldemort')
Just a couple things to give you ideas