If you like to give a little to charity without actually giving anything, you can install the new SocialVibe widget on your WordPress.com blog. What it does is that it lets you pick one of the available causes, and then a sponsor will pay every time the SocialVibe widget is loaded, of course showing the sponsor message to cover the bills. Doesn’t cost you anything other than screen real-estate, which it might very well be worth. More details on how it works in the WordPress.com Support area.
Self-hosted WordPress users can nab the plugin, and everyone else can find a suitable solution on the SocialVibe website.