^ agpgirl demonstrates an easier way to edit the image if you don't care enough to have rounded corners (or they don't look good in your image editor).
However, note that agpgirl's image is 115KB. This is because it is a PNG. The original file korin posted at the top of this thread is under 40KB. Most of the size difference is because korin used JPG format, not because of the dimensions of the image.
It is each user's responsibility to keep an eye on the file size of their signature images, so I would recommend that everyone use JPG format. And keep in mind that you can usually adjust the compression "quality" of your JPGs from the "Save As" window. Simply bumping down the quality a few notches can make the file size MUCH smaller, and you might not even notice the difference when you look at the image itself. For instance:
Look at this second image. Can you tell the difference? I can't.
But it's about 16KB in file size... 99KB less than the original.
To do this, I saved agpgirl's image as a JPG and used just a little bit of compression. Even if I used a maximum-quality JPG, the file size would still be cut in half! The moral is that JPG/JPEG format is really handy.
