If you are looking for a free way to stay on top of recent federal court opinions, then you should take a look at CourtListener. This website, created in 2010 by a graduate student at the University of California, Berkeley School of Information, is an alert tool for opinions issued by the 13 federal circuit courts and the U.S. Supreme Court. The website is updated daily, which means that all of the opinions of the day from these courts will be posted to the site by 5:10pm PST. You can browse by jurisdiction or conduct an advanced search for opinions, and you can download a copy of the original document as provided by the court.
If you choose to register with the website, you can also create custom alerts that will notify you daily, weekly, or monthly when new cases are added that match your search.