i was looking in my digitech products book (you know, the one you get if you buy any digitech product) and i looked at the set-up classed as alternative and i noticied a chorus pedal and i wondered what they do?
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This effect thickens up the signal to make it sound like more than one instrument. It can also add sparkle and warmth and give a standard guitar 12-string quality .

Digital and analogue chorus pedals are now available and these work by delaying the sound by thousandths of a second, sometimes with a slightly altered pitch, and then combining it back with the original signal.

from UG, not me
Classic example of chorus pedal use:

Nirvana - Come As You Are

Metallica - Nothing Else Matters (light chorus effect on the intro (sounds like one at least))
Check out the soundclips on Digitech's site if your still in wonder
PRS Standard SE
Laney GH100L with Marhsall 1960BV
Digitech Bad monkey
Marshall EH1
EHX Small stone
EHX Small clone