When it came to setting up Wi-Fi networks, if you knew what you were doing you would enable WPA security. This would keep people with a small amount of knowledge from gaining access to your network, which is very easy with the much weaker WEP security. No more! WPA security has now been cracked, rendering all but the most tightly-locked networks open for hacking.
Researchers by the name of Erik Tews and Martin Beck were the ones to do the cracking, finding a way to break the temporary Key Integrity Protocol (TKIP) in under 15 minutes. They haven't, however, figured out how to gain access to the data that travels between the PC and the router, so that's a plus.
So what should you do to secure your network? Switch to WPA2, which is still uncracked for the time being. And if you want to be one of those marginally-skilled Wi-Fi hackers? Grab the Aircrack-ng Linux program, which has already had this new code added to it.