Quantopian today announced that it has implemented live trading for algorithmic trading models coded in its backtesting engine. Right now, it is only available by invitation, but those who are interested can sign up for the beta program. I also appreciate that Quantopian is up front about the fact that it expects some anomalies to show up, both because the technology is still being refined and because their data provider uses real-time, unfiltered data (i.e. no filtering of bad prints). In any case, what are you waiting for? Head over to Quantopian and start automating your trading.