He looked a little like Farnsworths' gay lover, but don't think it was him. I was trying to figure it out too. Seems like Gov't, but the idea of another visitor is interesting too, but less likely.

It was a Man in Black. Could be human could be ET.
It's not "Sci-Fi", it's SF!
"Calvinism is a very liberal religious ethos." - Truekiwijoker

But he landed in the USA so likely not CIA.
It's not "Sci-Fi", it's SF!
"Calvinism is a very liberal religious ethos." - Truekiwijoker

For some reason I thought it was another alien watching Newton. He mentioned seeing beings from his planet on Earth. I thought they didn't want to be discovered and capture him when he was building his rocket. According to Wikipedia it's just CIA though.

I mention him in my previous post, I never could figure out who it was either. You see another unknown man also in a suit and tie standing over Newton later in the movie, right before Newton finally is able to leave his locked down apartment. It's at the 2 hour 3 minute mark in the extended director's cut. You see Newton laying asleep in bed with empty booze bottles around him and a man in a suit standing over him. With reddish blond hair like the guy at the beginning of the movie but he has a beard in the latter scene. I'm assuming it's the same guy and never could figure out if it's a member of the government tracking Newton the whole time or even another "visitor" that Newton says he has seen signs of, who may be tracking Newton. I have no other guesses beyond that.