I've been working on integrating WordPress to match the look and feel of existing websites. This one has the blog in a directory one level below the web root. The blog is linked in and matches the look of the rest of the site (which uses a CMS I wrote in Perl).
jQuery / LiteBox 2 Plugin
Custom Logo and search box in header.php
Top navigation toolbar
Shares majority of CSS with rest of site (WP classes "re-wrapped" in divs to match layout).