I keep a sticky note on my computer where I write down all the words that I come across, either randomly on the internet, or by reading. (Have you guys noticed how many ridiculously obscure words David Foster Wallace uses?)
My most recent 5:
Threnody: A song lamenting the death of someone.
Vermiform: Having the characteristic of a worm or snake.
Quotidian: Reoccurring, regular, mundane.
Inchoate: Incomplete, rudimentary, unfinished.
Lachrymose: Teary, sad, inspiring crying.