Extended Text provides a text widget which can be hidden by adding page ids to the widget.
MyPress allows you to customize your WordPress admin area and login screen with your logos and your color scheme. MyPress also gives you the opportunity of making your own unique administration area without touching code and without having previous knowledge in CSS or HTML.
ShushThatNoise allows you to hide unwanted comments without deleting them. Edit the comment and wrap the offending text in [shush][/shush]. Readers can choose to read the hidden comment by clicking on the “Show” link.
Simple Music allows you to easily play any MP3 as a sidebar widget on your blog.
WP Socializer is an advanced and powerful plugin for adding social bookmarking links, retweet buttons, Google buzz buttons, Digg buttons, Addthis buttons, Facebook buttons with inbuilt setup.
All in One Webmaster has options to add Google, Bing, Alexa, Blog Catalog, Yahoo’s Webmaster and Analytics code (meta tags).
FourSquare Integration for WordPress allows you to view your last checkins either as a list or on Google Maps on Pages and Posts.
Query Multiple Taxonomies allows you to filter posts through multiple custom taxonomies.
Twitter Goodies will show your twitter tweets under Sidebar Area (Widget), Post and/or Pages.
WP Archive-Sitemap Generator generates a simple `Archives/Sitemap` based on your blogs posts and pages.
WP Google-buzz automatically displays a Google Buzz button for every post.
YOURLS: WordPress to Twitter is the bridge between YOURLS, Twitter and your blog: when you publish a post or a page, it will use your own YOURLS install, either hosted on the same webserver, or another server, to create a short URL for your post and send it to your Twitter account. The plugin also works with public popular services such as TinyURL, tr.im, is.gd or bit.ly.