Been watching Heroes and loving it. Recently we read a list of names for the characters’ alter-egos. Inspired by this, I bring you my inventions:

Charlie – Flashdrive
Claire – Rebound (or, if you want silly, Anti-Maim)
D.L. – Fade
Eden – Hpnotiq (because somebody’s got to have a cool alternate spelling)
Isaac – Visionary
Micah – Wiretap (because I think Spark would get me in copyright trouble)
Nathan – Rocketman (I’m not the man they think I am at home . . . )
Niki – Evil Twin
Peter – Tabula Rasa (because anything with Mirror sounds too much like Mirror Master)
Sanjog – Dreamtime

I can’t think of anything for Mysterious Haitian Dude, and I just can’t bring myself to use Thought Police for Matt or Mr. Fusion for Ted. And I agree with the OP that Hiro is just Hiro because he rules.