Garth Gutenberg

Lets you display a twitter feed in a sidebar widget. 
Caches last successful tweet retrieval and only updates if it successfully gets a new list from Twitter. 
Practically every element has a unique class so that it’s highly customizable via CSS.
There are various configuration options including:
<ul>
<li>Title</li>
<li>Twitter Username</li>
<li>Max Tweets to Display</li>
<li>HTML to override the View All link</li>
<li>Time Placement (whether or not the timestamp should appear before or after the tweet)</li>
<li>Time Format (uses PHP’s date() function for formatting)</li>
</ul>

GG Twitter

Automattic

Nick Momrik

Beau Lebens

Tim Moore

Niall Kennedy

Display the latest Tweets from your Twitter accounts inside WordPress widgets. Customize Tweet displays using your site or theme CSS.
Customize the number of tweets displayed. Filter out @replies from your displayed tweets. Optionally include retweets. The widget plugin automatically links usernames, lists, and hashtags mentioned in Tweets to keep your readers on top of the full conversation.

Wickett Twitter Widget

Future upgrades to Wickett Twitter Widget will only be available in Jetpack. Jetpack connects your blog to the WordPress.com cloud, enabling awesome f …

GG Twitter vs Wickett Twitter Widget