Here is a free utility from Microsoft that I use all the time:
http://www.microsoft.com/windowsxp/d...powertoys.mspx (Called Image Resizer part way down the page.)
You install it and when you want to use it you open the picture you need to resize and then right click on it. That gives you the option to resize in several different sizes - I use the default 640X480 when I'm going to put it on the internet. It gives the picture the same name as the original with (small) after it. Works great!