Neat Ideas listing?

Has anyone compiled a list of Neat Ideas in conlanging? (Rather than
"neat conlangs" that just happen to implement neat ideas.)

E.g., I know the 'continuous adjectives' thing has come up before; I'm
talking about things like that, ones where just the idea of doing it
could be enough to spark something.

Would be better of course if linked to an actual implementation (e.g.
Ithkuil etc).

Sound at all familiar?

 - Sai