Oh my god, is that ever inaccurate. It's a trust available only to accredited investors that happens to invest in Bitcoin. By that logic, you can put just about anything in your IRA.

Here's a random Google result about the variety of bizarre funds out there: http://money.usnews.com/money/personal-finance/articles/2009...

edit: corrected my mistaken categorization of SecondMarket investment vehicle.

edit: invest in fine art (sorry, no funds open to new investment) - http://www.thefineartfund.com/index.php/en/products-and-serv...

edit: invest in vintage wines - http://www.wineinvestmentfund.com/index.aspx ... and so on.