Someone shot me an email and asked me where I could find earnings breakouts when they first come out...
I told them zacks.com is a good place. They'll tell you which stocks had positive and negative suprises. I was trying to find an earnings RSS feed to put on the blog but I couldn't seem to find one.
Anyways, you can go to zacks and you'll see the daily earnings surprises.
However, I did not see PENX, listed. I found this stock because I was checking out the daily %winners. PENX was up their early. Often times I check the daily winners trying to catch the stocks that are on the move for a reason, that is a deal or announcement of new management or something that the street may take awhile to adjust to. The reason is not the deal itself that they will take awhile to adjust to, but if it's a smaller cap, and/or has a low float, and some institutional ownership (need a demand from someone that can really move it). The street will often take a few days for it to reach it's potential.
Anyways, I've also been told that wallstreet journal are good places.
If you want to make sure to catch them, I would check the daily % winners around an hour after the market opens. You can check the news and find out what's the reason for it.
update: Another good way to find strong earnings stocks that breakout (as opposed to stocks that are breaking out on the announcement of earnings) requires a little bit more work, but it's worth it. Grab an IBD on Thurday, and enter in the IBD 200 into finviz screener. Any stock in the IBD 200 is going to have strong earnings and momentum. Now the trick is to identify chart patterns that look good. This of course requires the skill of being able to know what a good chart looks like. For more information on learning about technical breakouts, I suggest Encyclopedia of Chart Patterns By Bulkowski. If you don't have the money his web site the pattern site has some good information.
Also, if you want to learn more about earnings, stock bee has plenty of stock earnings trading strategies in his informative articles.