Do you want to show your users what is being said in Twitter about a certain keyword? Want to increase your keyword density for a word? This plugin does exactly that.
You can configure the keyword, Tweet’s language and the number of tweets that appear on the sidebar.

Twitter Keywords

Add tweets about a certain word, in certain language and from a specific user on your sidebar

Steve

This plugin uses custom fields to allow the page title tag to be customised and differ from the actual page title.
Both meta descriptions and keywords can also be added if required.
Page meta details can be modified on any publicly accessible post type, such as posts and pages, as well as custom post types.
Theme and plugin developers should note that it is possible override the page title within your templates by setting <code>$wppm_title = 'Newly defined title';</code> before the call to <code>get_header();</code>.

Page Meta

Adds the ability to override the page meta title and add in meta descriptions and keywords for pages.

Twitter Keywords vs Page Meta