As I haven't checked what sort of computer you are running Kgun this information may or may not be useful to you, but for people using Windows OS there are some very good built in tools for resizing images, batch processing them and even customising the sizes.
Annoyingly they are basically built into XP and newer systems but Microsoft never took the time to make them permanent features, or tell people about them, and this is one of their better tools, especially for the average user without expensive photo manipulation software like Photoshop.
You may be aware that by selecting images in Explorer/My Pictures and right-clicking you can choose to email these photos to a friend/colleague and a small box opens asking if you would like to resize the images. It gives you 3 or 4 basic sizes and turns 1.5mb files into 70kb files easily. I have told plenty of people how to use this when they are sending me all their latest baby photos, etc!
Well instead of having to email yourself these resized photos, if you go to this page
Microsoft PowerToys for Windows XP and download the ImageResizer tool (521kb), this will put a tool in your Explorer browser right-click menu that allows you to use the same procedure and built in tools to create copies in the same folder that have been resized. You can easily shift them afterwards as they are all named differently and do not overwrite your original files.
I have installed this on many clients' computers who need to send me product photos to update their websites and when I don't necessarily need 25Mb emails!
For any Windows users I think this is a great tool. You will see a variety of other tools that may be handy too.