I've read about people who have been lucky enough to see a part of a csi, csi new york or csi miami episode being filmed and wondered if there were any sites that let you know ahead of time where and when any of the series were going to be filmed. Its just a pondering for the moment but I'm very much an analytical curious person so seeing an episode being filmed would really appeal to that urge I get to know exactly how something is put together. Since I'm over the pond in uk I would have to plan it within a holiday, so would be unlikely for at least a year so nothing concrete, but any ideas aside from booking a holiday to L.A where I know most of at least csi new york and miami are filmed (don't know about csi) and hoping for the unlikely event of striking lucky.
I know CSI:Miami and CSI:Las Vegas are filmed in California. I think CSI: New York filmed in New York, I'm not sure. Once in a great while, CSI: Miami filmed in Miami, CSI: Las Vegas filmed in Las Vegas. I hope this help.
CSI: Ny is also filmed in California, except for a week or so of exterior shots in New York. Most NY shows, like NYPD Blue and MacCloud, film on back lots and similar architecture in LA, except for those exterior shots. The production companies film several episodes of those scenes each visit. One exception is Law & Order and its spin-offs. They ARE filmed in New York.