Web-Based Photo Editors
If you need to do some editing or processing of your digital images, you don't really need any installed software; there are plenty of free online resources you can use. Some give the basics, such as resizing and color correction, while others are pretty sophisticated products allowing almost Photoshop-like abilities; so they could be very handy if you need to do some editing from someone else's computer, for instance. MakeTechEasier has a round-up of 5 candidates here. I have used Pixlr myself a couple of times in the past, and it's actually pretty great.