You know the situation probably: helping someone to process images but no usable software around. With an internetconnection its possible to download imagemagick, the incredibly versatile and free software.

But it is even easier: use the imagemagick software online over the internet using a great wrapper around it: MagickStudio.
Some practice is required and it certainly helps if you are familiar with imagemagick terms, but hey: you get a rich suite of tools for free to help you out!
The software can be installed on your own website or used online at Net4tv.com.