Free Plugin adds stereo width to mono sources

This is by no means the only plugin offering this effect but it's free, it's pc and mac compatible, and it comes from Voxengo, which has been one of my favourite developers for many years.



Description from the website:
This professional audio plug-in implements a classic technique of transforming a monophonic track into spacious stereophonic track by means of mid/side coding technique. This plug-in is most effective on monophonic sounds without overly sharp transients: it works great for both acoustic and electric/overdriven guitars, synthetic pad sounds and even vocals.

While you are there, check out everything else on that website: the quality of Voxengo's effects is superior or equivalent to some of the best plugins on the market but the price tag is always reasonable, and some are truly unique; sadly most of the effects are still windows-only, but we hope to see more mac compatibility soon.

Get it from http://www.voxengo.com/product/stereotouch/