For you HF listeners and SWL's out there, there is a new feed out of JFK dedicated to two ARINC frequencies, 129.9 and 129.4, the former used for oceanic traffic and the latter for continental communications. A PDF coverage map is attached below.
Traffic on 129.9 is primarily aircraft departing or over-flying the New York area and headed to Bermuda, Florida or Caribbean destinations. They customarily will contact ARINC ("New York") five to ten minutes prior to their estimated entry into HF ("shortwave") oceanic airspace coverage at any one of a dozen or so way-points located between 240 to 260 miles southeast of JFK (image attached), request an HF frequency assignment and provide their four-letter SELCAL code. ("Selective Calling", a tone alert system that allows pilots to be reached without them having to listen to the constant static and noise on the HF bands) Minutes later they will report over their entry point with altitude, speed, estimates to next way-point, fuel aboard and occasionally winds aloft or weather. Sometimes their initial contact will be shortly after takeoff from JFK or even from the field. Occasionally there will be phone patch requests on this frequency when unable to contact "San Francisco" on 129.4, in fact today I heard a pilot initiate a patch to dispatch while sitting at the gate at JFK because he was getting no response from the terminal to his push-back request and he wanted somebody to get them on the phone and kick their ass.
Anyway, 129.9 is great for tracking flights out of New York and bridges the gap between VHF and HF coverage. Just listen to the frequency assignments and, if not covered by Dave's HF feeds, tune it in on your own Harris RF-590 or W/J HF1000
Most of what you will hear on 129.4 is phone patch activity to "MedLink", company dispatchers and/or maintenance to deal with in-flight medical or equipment issues or emergencies. As these aircraft can be as far as 280 miles away you will never hear the ground stations, which are spread all over the continental US.