Out of pure nerdery, I have a Raspberry Pi based ADS-B receiver connected to an antenna at home which tracks all line-of-sight aircraft. I feed that data to numerous aircraft tracking sites such as FlightAware, adsbexchange, RadarBox, adsb.fi, and Flightradar24.

Here's a link to a live map of all the planes that are within line-of-sight of my house. This can be up to 50+ planes during busy times, or zero in the very early hours.

Van Nuys Airport has more private jet traffic than anywhere else in the US, especially "celebrities", and all those planes will pop up on my ADS-B receiver.