I think this maybe a feature request more than anything, but perhaps someone has a work around!
I have a comp with 200+ layers, around 40 or so have movs/mp4 etc and finding that everything is grinding to a halt when working. I don't need to see these vids while setting some stuff up and think a simple Disable Footage/UnPreview Media (or similar) button along the top of the timeline, next to Shy Layers for example, would be extremely useful. I wouldn't what them switched off entirely - perhaps just filled with a solid colour which could be set in Preferences.
Turning on and off manually is prone to error, I've tried giving the media content their own label colours and selecting that way but they are already grouped. Anyone else found this an issue and a quick solution?
Use the layer tagger script found on AEScripts.
WOW - look at that! Thanks Mylenium - I wish I'd asked two weeks ago (or, rather, 10 years ago)!! Adobe should buy this and build it in