Hedging against the bubble popping - where's the leverage? My friend has a rather large store of bitcoins that he bought about a month ago. I think it makes sense for him to hedge his recent gains, since the price run up looks like a bubble.

What is a high leverage way of doing this?

I looked at ICBIT but the counter-party risk in the face of a market blowup is large.

I was thinking Intrade, but they are apparently blowing up. Settlement in fiat preferred. My friend lives in the US.
Like @David Ogren suggested, you are just supposed to sell part of those coins.

Dunno why are you trying to make it so much more complicated.