I was a mythology nut back in my early days of the internet (okay, okay, I still am), so I took the name Troy and added an "a" at the end to make it more feminine. Troya was already in use on IRC, so for some reason I decided to be a cool kid and added "tz" to the end instead of coming up with some new nickname. So now, I am Troy + a + tz just about everywhere, except on the websites I've registered on before ~2005-2006, where I'm still Troya.
Riveting, I know.
http://t0.gstatic.com/images?q=tbn:ANd9GcRjevSqJIZ77C6zNqvIaJRHZZWJJ45J5lMi4hV8pUVbYTlL4B3dCH3wRuBV.
I thought it was because you knew how to use photoshop.