I've thought about this as well. I used to record my DJ sets with an mp3 player that had line-in. I'd just spin, record, and then upload when I got home the next day (and even do my podcasts this way on my home gear). An iPhone app that did the same for name brand DJ's would be excellent. They could record or even stream to a room of their own (or their label or the nightclub itself). I'd love to login to the Club Amnesia room and be able to listen to sets from their Ibiza parties in the last week. The right execution would totally work for EDM fans I think. I tried something similar with podcasts: bestdjpodcasts.com but what TT has is much more compelling IMO.