I've been buying electronica stuff from bleep.com and juno, and I have to say that the whole digital download experience is really something. You listen to clips, you say "I'll have that", you pay £1 or so a track, then in minutes it's downloaded to your HD.
Someone was telling me they were in a club a couple of months back, and someone asked the DJ if they had a certain tune, and he said no, but he had a 3G card so he went onto the internet, bought the tune, and then played it.
Pretty smooth.