Funny how this old thread got bumped, because I'm actually LST'ing autos right now. In fact, you can even top them (I snapped the meristem on one of them about halfway through the grow, she recovered but is about 1ft shorter than the others.) One thing I'd watch out for though is the stretch. My canopy was already full to bursting halfway through, but my girls just kept on growing. Now I'm about 2 weeks from the chop and most of my colas have actually grown PAST my HiD...
Overall I'm impressed with autos, I didn't think they would be so robust. (Yes, I'm a first-time auto grower) I will prob grow them again in the future. My advice though for all indoor auto-growers is to make sure you have enough room.
*Edit* I'd supply pics but my girls are sleeping right now and I'm too cheap to buy a night light.