All Dj mixing equipment can be emulated using a PC,the mixer,the effects unit etc etc at a fraction of the cost.
Most of the music genres that fall into the Dj mixing styles on vinyl were original either completely produced on a PC using software,samples,tracked recordings or used hardware ( very expensive ) to do the same thing.
I'm not suggesting that if you love to fire up the decks and mix that you should see this method as a lessor form for mixing.
I'm simply stating a Fact the that theirs nothing you can't do with a computer ( production wise ) that you can do with a hardware mixer and decks,yet their are a huge and ever increasing amount of things you can do with music on a PC that you can't do with a hardware setup,Even if you had the money and resource's of NASA to finance it.
QUOTE from me
'As for mixing with turntables I'd recommend a beat monitor,you have them on each deck and by using a visual indicator can match the BPM of each record thus make beat matching allot simpler. '
QUOTE from lev
'I wouldn't to begin with. I find it puts beginners off what they are actually setting out to achieve, it makes them lose the focus on the music.'
I feel any visual Aid with sound can enchance the music,thats why all audio production programs also have plug-ins and visual effects so you can also SEE as well as hear the shape or form the music is taking.
to Quote lev
'heh, what sort of club are you thinking of? Are you able to quickly pull something else out, and mix it in promptly, or hack off the last 5 minutes of something if the crowd are suddenly not going for it?'
I'm thinking of many clubs that according to the other music producers I speak to on the Internet use PC's Style Dj's.
So long has you have a reasonably fast PC you can load a new track up in seconds or less,you can edit,cut,paste,hack of the last 5 minutes in virtual real time (on the fly).
You could apply filters and filter out a beat then layer in another one,apply a chain of effects,instantly change the BPM's of the tracks so they match precisely 1:1 - 2:1 - 4-1 simply by clicking your mouse.
You could even have a the monitor hooked into you PC measuring the Ambient temperature by the Dance floor so if the fast paced music you constantly like to bang out for 60 minutes is causing the crowd to over heat and dehydrate

you can have the computer turn down the Air conditioning tempreture & chill the music out until the dancers catch their breath.( their is a commercial Dj bot called HAL that does this ) of coasre because you are using a computer you not only have control of the music but also of any other electronic/mechanical devices that can be automated.
Lev Again
'This might just be me being an old fashioned ludite or something similar, but I have never known anyone to get any *real* fun out of running a couple of mp3's/wav's from a PC at the same time.'
I think you were just missing my point,I'm not saying that computers should replace mixing decks.Computer and music technology is now heading in directions that is trying to combine the best of both worlds,computer based studios try and use special effects to achieve the ( imperfections...? ) of some hardware systems because these quirks produced a warm style.
I could imagine in the future ( it could be done now maybe already has) Digital Decks that look and feel rather like their Analogue cousins but actually have no music on the records,rather the music is being tracked by the PC so what you have is a traditional 'PC emulation' mixing desks with the benefits of having desks you can place you hands on and the flexibility and editing power of the computer.
Their are software programs now where by using a dance MAT placed on the floor and or pressure sensors you can actually produce beats and music by DANCING. B)
I find that most people get bored of sticking to just one way of doing anything!Music is an Adventure ,so don't limit your experience,their is only one right way to make music,weather it be mixing,production,dancing,singing etc etc .. ON TIME .