Grokster is (or was) a popular file-sharing application and network that--like LimeWire, eDonkey, BearShare, the original Napster, and many others--provided the infrastructure that allowed millions of computer users to swap files, be they music, video, applications, or even plain recipes.

Grokster, the music and movie industry's poster child for copyright infringement, has been in court for a while, and just a couple of days ago, the Supreme Court determined that using Grokster for swapping copyrighted material is illegal. Grokster has shut down its service and will pay a $50 million settlement to the RIAA. Many services, such as eDonkey, have already closed down, and more will follow as legal costs mount. Really, the only alternative for these companies is to go legal (see the new Grokster). All this litigation can be traced back to a critical June Supreme Court ruling that allowed copyright holders to file suits against services that encourage their customers to illegally download music and movies over the Internet.

Here's what it means for you: You'll get a growing choice of services that offer legal media downloads for a price, and you'll see the number of classic P2P options diminishing. That said, as long as there are computers and Internet, restriction-free file sharing as we know it will never die; rather, it will just be slowed down.