It is an awesome yet simple tool. I’ve used it many times myself.
Call it a badge, sticker, button, or whatever you’d like. Create yours! You can customize the various attributes about the button, such as colors, text, width, etc.
The button maker is provided by Adam Kalsey. To use the button you create on your site, just right click the image and choose “Save image as…” or a similarly-named option from your browser. Check with your blogging provider for information on how to upload the image to your site after you save it.
Like the Button Maker’s font? It’s the excellent (and free) Silkscreen from Jason Kottke.