I did some experiments with my GoPro camera in the fall with some interesting results. I don't think anyone really wants to sit and watch siderods or pony trucks for 30 minutes but I think footage is worth having. It could possibly be used to look for trouble. Has anyone else tried using a GoPro on a train?

https://www.youtube.com/watch?v=c3Ix_d58TEk

https://www.youtube.com/watch?v=MCGrTeEy0vo

https://www.youtube.com/watch?v=UZdIsC3OCTI

https://www.youtube.com/watch?v=_UaG2yUUzWA

I just got a GoPro, but have only used it once so far, while riding the train, getting handheld/stabilizer-assisted shots.

I know quite a few others who have used a GoPro on trains - especially the guys from Dynamo Productions. A lot of their videos have some footage of GoPro in action - this is their channel: https://www.youtube.com/user/ELMSLines

I believe this video has a few GoPro shots that are nice: http://youtu.be/ePZzk3kzBXE

I've done a bit of experimenting with a GoPro. I occasionally work at a local 2 foot gauge operation in an amusement park. Since it's a park train, the FRA electronics rules don't apply, and as long as I'm not playing with the camera while actually operating the train, the management was OK with it. So I mounted it a few spots on the engine and cars, and then turn it on while the train was loading and just let it run for 1/2 hour or so until the trip was done.

It worked well enough, except for vibrations. The mount seemed to amplify them, and the small park train coaches are light enough that they vibrate and bounce at every joint. Even the cab roof wasn't much help. It was better, but still bounced and swayed enough to be distracting.

I need to do some experimentation on vibration resistant mounts. I can take a lot of the vibration out in post processing, but there's a problem. Along with smoothing out the vibration, it tries to smooth out the motion of the train as well. There's no way for the software to distinguish between the two, and so you get a bit of stutter-step effect in the motion. I want it to be smooth, so it appears it has to be smoothed out in camera.

I have found a powered 3 axis gyro stabilized gymbal that will help, but the dang thing is like $350.

I have used the Go Pro while filming, I normally sit it somewhere and then film with a hand held camera to get multiple views, I also sit it in the gauge between the rails as the locomotives run over, due to the small size. here is a link to one of my videos!
https://www.youtube.com/watch?v=2piMNWQqfbI

One of the neat things you can do with GoPros is time-lapse. It's a time-sane way to explore heritage railroads.
https://www.youtube.com/watch?v=6NYNBATdFNs