Hit 10000 words today, and I took a bit of a breather to mess with the plot outline. I've been juggling two different pieces of this book for some time now, and today I realised I can move one of them to the last 1/4 (ie. the end section), which solves the problem neatly.
Before this insight I kept streamlining and compressing one piece of the plot into the smallest possible chunk so it didn't delay the introduction to the other piece. (In past Hal Spacejock novels this has led to chunks of plot being compressed into thin air, which is why I have almost a million words of unused Hal scenes sitting in a folder.)
I don't know whether this plot outline will work, but that's what NanoWrimo is about - bang out the wordage and worry about where it all fits later.