Panels Everywhere is an advanced method to completely do away with Drupal's restrictive blocks system and instead use the much more freeing Panels Layout system to control how your pages look. Panels Everywhere modifies the page as it is being rendered to 'wrap' the content in a display and can even take over your page theme to do away with the need for a page.tpl.php.
Doing this requires that you set up a few things properly, because Drupal is not really designed for this kind of behavior. Be sure to read the README before trying to use this module.
This module requires both the Panels module, and the Page Manager module from the Chaos Tools Suite.
Themes with Panels Everywhere support
The following is a non-exhaustive list of themes that are known to have support for Panels Everywhere:
Tinsel - Garland converted to use for Panels Everywhere
Panany - Very nice simple theme by jwolf, has extra Panels Styles also.
AT Panels Everywhere - Jeff Burnz version of Adaptive Theme with Panels Everywhere support.
Provides a facility to allow users to tag other users in content. Users may tag themselves or other users, and user tags are enabled on a content type basis.
This module enable integration with products implementing the SRU protocol for queries against DB, this standard was created by Library of Congress (US).
SRU is a standard XML-focused search protocol for Internet search queries, utilizing CQL (Contextual Query Language), a standard syntax for representing queries.
Simple, professional¹, clean looking theme without the usual "Designed by..." credit links that you'd normally go in and delete anyway².
Theme has the standard block areas (header, footer, content, left sidebar, and right sidebar) with a professional³ color scheme and a contemporary-- well...... flavor.
Also, a few more things exist that make this theme different from others.