If you were wondering about specific venues, ie Royal Albert Hall, on their website under 'Etiquette' it says:
Cameras, video equipment and tape recorders are not permitted.
Please ensure all pagers and mobile phones are switched off before entering the auditorium.
http://www.royalalberthall.com/flash...info,etiquette
Not that anyone would actually hear their mobile phone ringing for this concert!!
I guess we'll all have to rely on good old fashioned 'memories'.... remember those?!!