I have some mpeg-2 (vob) video files copied from an unencrypted DVD that I need to slice up. I don't know why the learning process around video has been so slow for me, but I finally have some tools that I'm happy with.
On Windows, the other guys are using Mpg2Cut2. It works, but my only Windows machines run in VMWare (normally just for occasional portability testing), so that is painful for video editing.
On Mac, I was using MPEG Streamclip, but had some problems as I was slicing between keyframes.
On linux, I'm now using Avidemux and or GopChop. Both have excellent support for helping cut at keyframes (avidemux actually includes docs that helped me figure out why MPEGStreamclip was giving me inconsistent results). I'm happy to finally be doing the video processing back on my primary Ubuntu workstation, and I'm impressed at finding these video tools that are even nicer than the ones available on my Mac.