I'm very hesitated to use this plugin:Adicon Wordpress Favicon Plugin.
This is how it looks like:
I'm not sure if it will really work on a wordpress blog, but if I could sell 16 squares for 1$ per month, that means 16$ per month and 192$ per year. It's a nice extra for such a small thing.
You can download the plugin here. Please share your opinion about this addon, would you advertise on a way like this on an active blog?