We don't know how many airports total are being affected, but FAA computers at one of their facilities are having trouble processing data, which means flights everywhere are being delayed. So far CNN says LaGuardia in NY and Hartsfield-Jackson in Atlanta were affected, but radar and plane contact is fine. If you're flying today or tomorrow (like I am), you should get to the airport early. Or late, I guess, if flights are delayed. Maybe just show up at your normal time. [CNN]
Update: Oh and check out delays for airports around the country. As you can see from the image above, delays of 16 to 45 minutes are hitting flights EVERYWHERE.