Re: hypnopompic/hypnogogic hallucinations, I've had a fair few.
When drifting off to sleep, I quite often hear noises, usually like a distant bustling market and church bells. Presumably from a past life.
But quite often I wake up hallucinating wildly - sometimes these are very real and plausible things; sometimes geometric pattens spreading on the ceiling, as per Aldous Huxley's mescaline experiences; and very often I'll notice with horror that my pillow is crawling with wasps, or that my bed is filled with beetles.
Once I was actually woken (so it appeared to me) by an old lady leaning right over me saying "OoooooOOOOOoooooo". Quite freaky.
I can usually watch them with interest once I've realised what's going on, and see them slowly fade. Sometimes I can sort of keep them going for some minutes by laying very stilly and just watching. However, the insect ones always have me leaping out of bed shouting before I know what's going on.
The thing that makes working late the hardest, I find (and I probably shouldn't share this with people who also have to work strange hours), is the intrusive memory of that Simpsons episode where Bart has to get up in the middle of the night to help Skinner catalogue his stargazing. The radio alarm wakes him up, and says
Well, it's 4.30am, and time for the news... except there is no news yet, because everyone's still asleep in their comfy, comfy beds. Good night...
Gets me every time! I'm yawning now!