Well, copying and just changing a posisitions track in time isnt exactly what you are trying to achieve, I think.
If you use a second mic a few feet away, you'll end up with one mic sounding very intimate and up close, the other... well.. a few feet away. The farther mic will have more room ambiance (good OR Bad) and you might even want to use different mics. Compress the dog shit out of the farther mic and maybe bring it up behind the vocal some. Experiment, you may hate it or love it. Try lining them up in a daw though so you dont have phase issues.
Another popular techinique is to mult the vocals, and leaving the 1st vocal relatively untouched, lightly compressed, then compress the living hell out of the second one and eq it pretty dramatically, make it thick thick thick, maybe even pitch alter it a few little nuggets, and then bring it up BEHIND the main vocal, just enough to thicken up tha main vocal. This leaves the main vocal with its natural sounding dynamics, and the multed vocal to kind of add some thickness and excitement to it.
Experiment. Have fun.