Last year, MBlume suggested:
Someone should really write a prediction market using bitcoins -- it would be simpler for US-based users to participate.
This now exists at BetsOfBitcoin. I signed up one exactly one month ago.
So far, I've won 13 out of 13 bets. Mostly small bets and low yields, but winning is fun.
Except it's not really a prediction market. You could know the exact probability of an event happening, which is different from the market's opinion, and still not be able to guarantee profit (on average).
Less Wrong used to like Bitcoin before it was cool. Monthly threads popped up around the same time a pricing bubble brought mainstream attention last year. When the bubble popped, and price continued to deflate, discussion on this site stopped entirely. Was there a change of sign in the social status of the topic, is the topic fully explored, or has there simply happened nothing of interest over the last year?
If you are not familiar with Bitcoin, here is one intro I happen to like.
Kaj Sotala lists a number of previous threads on the topic:
Less Wrong seems like a good place to discuss recent developments, if one does not want to suffer the inanity of the officially unofficial forum. If you are not longer interested in Bitcoin, perhaps send your remaining balance to the Singularity Institute?