Male or Female, growing techniques?

I heard from a friend that it is possible to determine if a plant comes out male or female by certain growing techniques.

Is this possible? Has anyone else heard or read about this anywhere?

Personally this is the first ive ever heard of it and know nothing about it though..

Environmental factors are supposedly able to influence the female-to-male ratio... but from what I've heard, you'd need to be growing a LOT of plants in order to see the effects. I think lights with a cooler spectrum (like 'cool' CFLs and MH) used during veg are supposed to lead to more females, as well as lower ambient temperatures during veg... but this may be totally wrong, and again, even if it isn't, you probably wouldn't see any noticeable difference unless you were growing thousands of plants.

International Cannagraphic Magazine Forums - How to produce mostly females from standard seeds.

So far haven't found any of them to work for me.....