I wrote my first plugin, and it's called Auto Links. It is based on Kidder's Link Definer plugin, but has more functionality.
Auto Links turns keywords in your post for popular websites into links automatically for you. So if you use Yahoo in a post, Auto Links makes a link of it. Unlike the original Link Definer plugin, Auto Links will only do this once for each keyword. It would be over kill to turn every reference to Yahoo in your post into a link.
Also this plugin lets you put a graphic next to each link. You can use the one that comes with Auto Links or use your own, or turn it off altogether. You can also control which window the
link will open in, be it the parent window or blank window, or whatever you want.
You can get it here:
It's still in beta, but so far it seems to be working well. I need to make a admin panel for it, I know that. But any other feedback would be great!