[Timo]

You can do the phase trick using any program.

Take a copy of the L channel. Let's call this L2.
Take a copy of the R channel. Let's call this R2.

Take R2, invert the phase and add it to the original L channel.
Take L2, invert the phase and add it to the original R channel.

Voila. Awesome stereo width that goes far, far wider than your stereo speakers suggest, but gives utter shit mono compatibility. (If you now sum both L and R channels to mono the signal will disappear completely, because both L and R would cancel each other out.)

However, if you have a couple of channels spare on the mixer you can use these to split up the M & S channels (middle and side) and then use the faders to increase or decrease the stereo enhancement to the mix so that it's not an "all or nothing" effect.

But there are other, better ways to increase the stereo width without losing mono compatiblity (double tracking, delays, layering, etc. as mentioned).