AudioTeknikk has released MidSideMangler, a free mid/side effect plug-in for Windows.
The first release is a Mid/Side processor that is capable of traditional LR panning, MS balance but more interesting Mid panning and Side panning. Making you able to ie take a finished mix and move the centered vocal, bass and bassdrum put it in the left channel and the rest that is in stereo to the right in the mix. There has also been reported a really cool brain sucking effect on a stereo pad. This tool can provide some great stereo effects and give you a hand in the mastering of a problematic mix.
MidSideMangler is available to download as a freeware VST effect plug-in for Windows PC.
More information: AudioTeknikk