Open a .mov or .avi file from your camera using the QuickTime Player which you have upgraded to Pro:
Under the Window menu is a Show Window Properties item. A dialog pops up and you should see a list of tracks. Choose the Video Track, and then click on the Visual Settings tab.
Click on one of the circular arrows. Your movie will rotate 90° and you can now save it in a form suitable for friends and family.
I don't know why iPhoto doesn't do this. It should.