I remember you asking a few times about why the level "Mary Poppins Land" was labelled as such. Well I was browsing around Wikipedia and found the answer!

"Taxing: Level 16: Mary Poppins' land: reference to Mary Poppins. Appropriately enough, the level is upside down."

So there ya go ;)
There's a list of references in Lemmings level names here:

http://en.wikipedia.org/wiki/References_in_Lemmings_level_names

I always thought it was to do with the fact you needed to use the 4 floaters to have 4 Lemmings float down, like Mary Poppins had her umbrella. And what's it referring to about the level being upside down? Might be because it's almost half 2 in the morning, but looking at the level I can't see anything. =/

Looks like you're right. I'm glad that this forum is still the true Lemmings oracle, and not Wikipedia :D

Awesome stuff! Really awesome! 8-)

Hehe: Now back to the "Ceci n'est pas une pipe!" in Lemmings 2. Yeah, I remember this picture of the "pipe". It simply shows that this is really not a pipe, but a "representation" of a pipe! :D

Heh, I think you might be confused; that wasn't me. Though I have asked similar questions about other levels sometimes. I also know about that Wikipedia page and have considered adding to it (and asking the other forum members to help me do so) but haven't yet managed to find the time.