I used to play at weddings, 21st’s and house parties with a full PC! I used to cart my 15″ CRT monitor, tower, keyboard and mouse, just to go play. At that time I used Virtual Turntables by Carrot Innovations (no longer around) [http://sonicspot.com/virtualturntables/virtualturntables.html%5D. They had a great time and if I recall, I don’t think they really cared how I got the music going or what equipment I was using.
So, if you are planning to spin with a laptop, remember that it’s not as bad as carting a full PC around 🙂
Happy Spinning!