This post is a work-in-progress. Have a favourite that isn’t listed here? Shoot me an email below and tell me about it.

Online (no download, platform independent) Applications

GifWorks.
For GIFs, animated or no.
http://www.gifworks.com/image_editor.html

On Your Windows Computer

Image Resizer
http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx