So I made my first widget. I was looking for large colored buttons for my sidebar (I am running WP Page Widget to get custom sidebar for posts and pages). I found buttons I could use with shortcodes, but I wanted to avoid borders and padding around my colored button.
So I did some work myself, and put together an easy widget plugin. Just a few colors to begin with:
What it became was a widget with two input fields, one for the button text and one for a link. Only customization is the color of the button.
It is to be read about (and images) at http://heavysheep.com/plugins/colored-buttons-widget/ or to be downloaded at https://github.com/asbness/heavysheep-colored-buttons