I'm pulling this contract and will be working on an ETF w/ delivery option.  I'll be writing an app that will automatically update the bid/ask price of the asset in real time on GLBSE as the price of spot silver and the exchange rate of BTC/USD fluctuates.  The ETF will have a smaller contract size and hopefully create some liquidity since most assets on GLBSE seem to trade around 1BTC or less.