Bitshares does this: http://bitshares.org/ http://bitshares.org/ Their BITUSD has been tracking fairly well: http://www.cryptocoincharts.info/pair/bitusd/usd/b

Bitshares does this: http://bitshares.org/ http://bitshares.org/ Their BITUSD has been tracking fairly well: http://www.cryptocoincharts.info/pair/bitusd/usd/bter/1-month http://www.cryptocoincharts.info/pair/bitusd/usd/bter/1-mont...