In the past I've looked for this type of trading tool (inquired here on ET a couple of times) because I know from experience how useful this technology can be. I've been using TS' Radar Screen for free for a while with mixed results, but I'm always trying to keep up with this group of products as they gain in features and power. I was recently happy to find an interesting analysis on the web: http://www.swing-trade-stocks.com/stock-scans.html - take a look, there's some good info there. Of course I don't really know the author, Craig, but he has some good stuff in this article. Any additional information for more stock screening/scanning anyone can contribute I (and others on ET) would appreciate. TIA.
I've been using FinViz for a while. Lots of good info there plus it's free. Madscan is another(have not tried yet) but is fee based. I know of some who use TD Ameritrade for their scanner but not for trading. Just have to open an account.