Because I can’t ever seem to find it without several Google searches, here’s where you can get official twitter buttons, badges, etc. to put on your blog or website: http://twitter.com/about/resources
Also, this is a great WordPress plugin for displaying your Twitter followers: http://wordpress.org/extend/plugins/twitter-fans/ .
UPDATE: having problems with the above plugin not saying the number of followers correctly. It’s stuck at 101 on one site, where there’s more like 130.