(I prefer media.ccc.de over YouTube because it lets you download the video in at least a couple of formats, and sometimes offers alternate streams/languages.)
Just to make sure there are no misunderstandings: the mediacccde account is official:
> To mitigate this we have decided to open an official media.ccc.de YouTube channel to at least make sure users don’t have to suffer advertisements, incorrect licenses and incomplete metadata. This account can be found on https://www.youtube.com/mediacccde.
Most video players support changing the playback speed. In mplayer it's controlled with the '[' and ']' keys and in VLC it's set in the Playback -> Speed menu.
HTML5 video elements also usually have a playback speed property that can be changed in the JS console, so any site that streams fast enough can be sped up.
https://media.ccc.de/v/33c3-8151-dissecting_modern_3g_4g_cel...
(I prefer media.ccc.de over YouTube because it lets you download the video in at least a couple of formats, and sometimes offers alternate streams/languages.)