Heh. Most of the weird stuff I've done is pretty banal by MDC standards! I encapsulated and consumed my placenta, but that barely raises an eyebrow here. :p
I learned to write Hobbit runes and tengwar (Tolkien's Elvish script) fluently as a teen, and kept diaries in both for ages. My skills are rusty now, but I still occasionally use it for writing Christmas present lists. I discovered recently you can write in Gallifreyan and toyed with learning it, but I guess I'm old and boring now.
On a related note, I attended (outside, on the street) the Return of the King premiere, in a dubious Eowyn costume. I've had a tour of Weta Workshops, met a lot of the cast, been called "sweetie" by Richard Taylor, groped by John Noble, and visited a bunch of filming locations, including some more esoteric ones. Living in NZ, I've also met several extras. Oh, and I've seen The Fellowship of the Ring more than thirty times. So yeah, there that is.
Apart from that... I dunno. I make wedding cakes occasionally. That's not particularly esoteric, I guess, but if I mention it in real life it seems to impress people. An interview with me was once published in someone's thesis on siblings of children with autism.
Oh, and I went skydiving. Once. Found it underwhelming. And yes, that is SO not mind-blowingly original, but according to my mother it's the wackiest, craziest hijink a person could get up to short of scaling the Eiffel Tower painted blue and covered with weasels. I come from conservative stock. :p This is a woman who's still reeling from the daring feat of painting one bedroom wall aubergine; I think she's still half-admiring and half-embarrassed that I henna my hair - to a shade everyone mistakes for natural, no less. Poor Mother. Still, she's supportive, except for the skydiving thing. She made my Eowyn costume, and that's something.