Save Flash Video under OS X (firefox)

Once upon a time, in Linux, it was possible to copy the files being downloaded and played by the Flash plugin out of /tmp and to wherever for later viewing. I was pretty sure this was possible under OS X. And wouldn't you know it, it is. But the files were harder to find. They're stored somewhere under /private/var/folders. I did this to locate them:

find /private/var/folders/ -type f -exec file {} \; 2>/dev/null | grep Macromedia


To figure out the top-level folder that contained them, a google query showed me this thread which clued me in. I don't know if someone pointed out the exact location later (tl;dr) but when I saw the bits about /private/var/folders I did a find in a terminal.

Removing Linux from OS X (to redo Bootcamp)

I wanted to remove Linux and try Windows (for some steam games) on my MacBook Air, but I had a little trouble. Using the Disk Utility (graphical program), I was only able to merge the existing JHFS+ file system with my Linux partition, but It wouldn't touch the swap. You can't just launch Boot Camp at this point because it will see the multiple partitions and refuse to run.

I tried to merge using the diskUtil command line, but it gave me the error: Merging partitions encountered error "Couldn't read partition map (-69876)".

So, I erased the volume and replaced it with a HFS+ with journaling. Then I launched the Disk Utility and it refused to let me merge them. For posterity, this is the command I used to erase:
diskutil eraseVolume JHFS+ new /dev/disk0s3

The result is that I had two Journaled HFS+ partitions that still couldn't be merged, but once I erased the volume from within the Disk Utility, it let me grow the remaining partition to fill the space. Boot Camp happily ran and created a new Windows Partition after that.