Lar Schlichting shows the new functions of the CDJ-900 (which are also included on the CDJ-2000s). Connect 4 CDJs together via USB, use a single memory card, hard drive, or ipod to hold all your tracks, and explore the new display and library functionality to sort by categorically by artist name,...
A really basic DJ trick you can do with your headphones. It works even better with an FX box attached (i.e. Mini KP or KP3) or a DJ mixer with decent on-board FX (i.e. any of the good Pioneers).
DJ Ty highlights some of the major feature differences between Native Instruments Traktor Scratch and Rane Serato Scratch Live. There is only $60 difference between Traktor and Scratch Live (Traktor is more).