The 181 Free Twitter Buttons, Badges, Widget and Counters to Help You Find Followers article links to a lot of cool twitter images you can use on your website or blog such as:-

and

Ultimately I went for something a little simpler:-

You can get an image similar to this from the http://labs.creazy.net/twignature/ and although the site is in Japanese you can easily see how to complete the setup form to produce your own twignature.

• Enter your twitter username into the “username” box
• Select the type of twignature you want (see bottom of the page for the different representations)
• Click Make and you’re done :