I was trying to batch-rotate a whole bunch of photos today in Ubuntu 12.04 (it's 2014; maybe it's time to try out Trusty Tahr) but my usual solutions just weren't cutting it. Shotwell doesn't even have batch options, as far as I can tell. I've used digiKam before for batch editing but it doesn't even appear to import files anymore. Luckily, I found the Nautilus Image Converter. It can rotate and resize images right from the file manager, just like in, um, most recent versions of Windows. Anyway, problem solved.