Invisible People

[Rhys]

I remembered an invisible thingy too, wondering if somebody can help.

Basically, all i remember is that they're not actually invisible. But people don't notice they're there at all.
I kind of remember a quote going something like

"so are we invisible?"
"not invisible, but they can't see us - to them we're nothing more than a passing thought"

[Rev. Powell]

This is probably not right, but those lines remind me of something the angels said in WINGS OF DESIRE (black and white, subtitled).  Maybe it was from the American remake, CITY OF ANGELS (with Nic Cage and Meg Ryan)?

[KreepLX]

I think I remember an old Star Trek episode like this. I think they were moving really fast and when they were around the people in regular time, the regular time people could hear a buzzing or something like that. Do you think it could be an old Star Trek episode?

[Hibbins]

Some of it sounds like Ghost(1990)
http://www.youtube.com/watch?v=uW7VjGP-Wrk

[CaptnTripps]

this one is bugging me, because it sounds so familiar...still searching. 

[CaptnTripps]

This is probably not right, but those lines remind me of something the angels said in WINGS OF DESIRE (black and white, subtitled).  Maybe it was from the American remake, CITY OF ANGELS (with Nic Cage and Meg Ryan)?

I second the possibility of City of Angels, maybe ill rent it here soon.

[Keir]

I think I remember an old Star Trek episode like this. I think they were moving really fast and when they were around the people in regular time, the regular time people could hear a buzzing or something like that. Do you think it could be an old Star Trek episode?

That was the first thing I thought of as well, only I'm not so sure it was a Star Trek episode.  It's actually something I've been trying to remember for a long time.  Some other suggestions people have given me were an episode of Twilight Zone (Elegy) and an episode of The Outer Limits (The Premonition).  The Premonition is very close in concept, but it doesn't have the quote mentioned, or the bit about them buzzing.  Also, I seem to recall it was in color, not B&W, and I thought it was a movie not a TV show (but of course I could be wrong).  Would be great if someone could solve this mystery.

[Jack]

There was something like that in the first episode of the TV show Torchwood. There was an entrance to a secret facility, and even though it was right out in the open, the main character explained that nobody noticed people going in or out of it because, well, something very close to your quote about being a passing thought.

[GoHawks]

Basically, all i remember is that they're not actually invisible. But people don't notice they're there at all.

I think I remember an old Star Trek episode like this. I think they were moving really fast and when they were around the people in regular time, the regular time people could hear a buzzing or something like that. Do you think it could be an old Star Trek episode?

I don't think this is what the OP was looking for, but there was an episode of "Space Academy" where at least one person somehow became invisible, I think because they were moving really fast and just couldn't be seen.  (Or was it the sequel "Jason of Star Command"?)

More recently, "Stargate SG-1" had a few episodes like this:

In episode #3.21 "Crystal Skull", Daniel Jackson becomes invisible after looking into the eyes of a crystal skull.

In episode #4.3 "Upgrades", the team wear special alien armbands that give them greatly increased speed and strength; when moving fast they are basically just blurs that "normal" people can't even react to.

In episode #9.18 "Arthur's Mantle", Sam and Colonel Mitchell get "translated" into an alternate dimension where no one can see them but they're still there.

In episode #10.12 "Line in the Sand" Sam uses the same technology to hide a building and the people in it.

It's not likely, but if any of these are what the OP was looking for, it is probably SG-1 episode 9.18.

[JaseSF]

Actually the "Star Trek" suggestion is pretty good - "Wink of an Eye" has aliens (Scalosians) who cannot be seen because they are moving at a faster rate of speed than the crew of the Enterprise. They do sound like buzzing insects to the crew however.

[Newt]

I was thinking of that Star Trek ep as well.  There was also an ep of Star Trek: The Next Generation (eta: "The Next Phase" season 5 ep 24) that had Geordie and Rho out-of-phase so they could not be seen.  The line qutoted in the op seems similar to something Geordie said in that one.

[Bargle5]

I'll add one more, but it's probably not it. There was an episode of "The Wild, Wild West" called "The Night of the Burning Diamond " that dealt with a sped up person. 
The speeded up motion power was provided by diamonds. It also used the high pitched noise effect when someone was moving at speed.

http://www.imdb.com/title/tt0748513/