Way back in the Stone Age, I went to DexCon 3 here in New Jersey in 1994. (I still have the t-shirt with its great Phil Foglio illustration!) In the dealer room, I saw a weird sort of die in the bins. It was like a d20, but bigger because it had 30 sides. Thirty! I was still pretty new to convention gaming, and splurged, buying three of them. They came with a leaflet from Lou Zocchi with a d30 table for generating some random something or other; the chart has been lost to the ages, and the details escape me.
And they've sat in my dice bag for a decade, since other than the one chart, I had nothing to use them with.
Fortunately, that has now changed! I came across this post on Dave Larkin's blog, and it's got a bunch of stuff to use them with! He even has started an Order for d30 enthusiasts; it's probably the most prestigious honor I can hope to attain!
Of course, now I can't find any of the dice I bought oh-so-long ago...