One thing no-one has really discussed is, is just spinning some mp3's really 'DJ'ing'?

I mean, I rather doubt many here on this forum have gone out to a nightclub or rave where REAL 'DJ's' do their thing. The best of them, like the best musicians, are capable of pulling something out of their equipment lesser performers can't find. Not ALL of them simply download other DJ's mixes and mashups. Some of them are as creative and technical as any of us.

But it seems like anyone that wants to sit behind a laptop and program the order of what their iTunes program plays next wants to call themselves a DJ...

That's pretty much like a One Finger Chord, out of time one finger melody arranger player calling themselves a 'musician'. I suppose, in the MOST broad definition of the word, they are. But no musician would agree with them

And no REAL DJ will ever admit that running an iPod on break is DJ'ing.

Hire a REAL DJ for that wedding, chas. Don't settle for any old kid with a laptop and some speakers and lights! What you see isn't necessarily what you get!