Audio jacks? We don't need no stinkin' audio jacks: two Numark
2-channel DJ mixers now connect via USB, instead. Hook up two
Windows/Mac laptops to the mixer and mix directly without an audio
interface, complete with cross-fader, gain control on inputs, the
works. You don't even need USB drivers on either platform, thanks to
class-compliance. More interestingly, you can use the same USB
connection to record your final mix, so this is ideal for DJs who need
to keep track of their sets.

  • DM950USB
    is the more compact and affordable of the two, though it has all the
    basic 2-chanel mixer features you'd expect. Street price around US$60
    (!)
  • DXM01
    is 24-bit, has "intelligent bass enhancement, far superior to EQ",
    all-digital faders, and various other goodies — and looks prettier.
    Street price around US$250.

In fact, this is just as ideal for any laptop musicians — including
non-DJs — who want to work with two laptops. And if you're concerned
you're required to use the two USB ports, you're not: 2 line, 2 phono,
1 mic, too. So that could be one laptop, one turntable, a feed from a
digital audio interface if you need to plug a mic into the computer,
whatever.

I'm not a DJ, and I'm ready to go grab one. Stanton hasn't added USB to
their mixers yet, as near as I can tell. Betcha they will.