The Night Flight Call List (NFC-L)
http://birdingonthe.net/mailinglists/NFCL.html - Link to recent NFC-L postings
http://firstname.lastname@example.org/maillist.html - Older NFC-L postings.
Sites involved in recording and identifying nocturnal flight calls of migratory birds:
http://www.oldbird.org/ - Old Bird, Inc. Main site for anyone interested in how to record and interpret nocturnal flight calls. Also the place where you can order Flight Calls of Migratory Birds CD by Evans and O'Brien. At this site you can download the call detector software (Tseep, Thrush and Dick) as well as the call sorting software (Glassofire).
http://www.birds.cornell.edu/birdcalls - Call Notes and Flight Calls. Excellent site by Steve Kelling. Recordings and spectrograms of call notes, flight calls, and nocturnal flight calls.
http://www.wvbirder.org/noc.htm - Matt Orsie, WV Birder. Spectrograms of nocturnal migrants from Jefferson County, West Virginia. Excellent bird photographs and WV birding info as well.
http://www.surfbirds.com/blog/tomstips/17182/Sonograms+Part+2%3A+Slow+Playback+and+Calls.html - Tom's Tips, Technology and ID Technique for Birders. See September 2010 Blog entry for the some interesting insights into ID'ing NFCs.
http://pjdeye.blogspot.com/ - Bird Songs and Calls. A blog about the bird sounds of eastern North America and beyond using original recordings and sonograms. Some nice daytime bird calls here as well as a few blog entries with NFC recordings.
http://earbirding.com/blog/ - Earbirding.com. Recording, identifying, and interpreting bird sounds. Interesting and informative site by accomplished recordists Nathan Pieplow and Andrew Spencer. A worthwhile place to spend some time for any NFC enthusiast.