I recently shot a bit of video on my still camera. It involved a flag pole, so naturally, I held the camera in portrait orientation. This presented me with an issue when I got the video back home to my desktop. I had shot it sideways, but no one would want to watch it that way, and I had no access to a video lab or the cash to buy video processing software.
A helpful message board poster pointed me to VirtualDub(http://virtualdub.org), which is “a video capture/processing utility for 32-bit Windows platforms (95/98/ME/NT4/2000/XP), licensed under the GNU General Public License (GPL).” It boasts a long list of filters, some built in, and some from third parties.
I applied the “rotate 90 degrees” filter, chose a compression method, and had a finished product after a few clicks and a few minutes.