I managed to turn around a lemming on top of a steel area,and it's possible to do with just 2 builders and a digger.
Here's a screenshot of the basic idea on this...my next pack will certainly contain a level requiring this :)
(http://it.travisbsd.org/lemmings/lemmingswelt/index.php?cmd=get&file=screenshots/build.PNG)
Does this require you to put the steel area in mid-air? That's kinda frowned upon since the steel area won't be visible without peaking at the level construction at LemEdit.
I'm also somewhat confused since if I recall, when a digger hits steel he normally does not turn around......
It looks like he built a few steps, dug so that some pixels of the last step remained, and then built into it. If that's correct then it could happen on any steel block, the only important thing is that the digger stops.
Not marking where steel areas are is one thing, but requiring people to guess where they are in order to pass the level? Come on...
I just said that the trick could happen on any steel block, being in mid air is irrelevant to the success of the trick. Levi also said that the screenshot shows only the basic idea, not a specific example of how it will be used in a level.
It hasn't anything to do where the steel area is...but it won't work if the steel area is too big.
In this case the steel covers just the block,and nothing else.
Here's what I did:
-Build a few steps (at least 4)
-Dig away 3 pixels (one pixel remains mid air somewhere)
-Build again
-The builder turns around due to that one pixel that was sitting mid-air
By the way,for some reason it seems that this only works with builders going left to right...