OK, I know already. Is there any way to stop this from appearing?

bump.

Nobody knows or it is just impossible?

What player?

Youtube, Vimeo, some, uh, other sites that I visit but won't name...

They all seem to show 'Press Esc' for a couple of seconds. I assume it is part of Flash but havn't found a place to turn it off.

Create your own flash player. Or slightly easier - downlod the source for JW Player, modify it and recompile.

Chris is quite right. You use Vimeo or Youtube, you accept their player, so far as I know.

Flowplayer and JWPlayer have other options, you can modify them freely.