Lucidica is a theme for Google Reader. It's been tested in Google Chrome, Safari 5 and Firefox. Lucidica is perfect for use with Fluid if you're looking to integrate Reader with your desktop. Lucidica is free to use, released under a Creative Commons Attribution-Noncommercial-Share Alike License. This means that you are free to download the source and modify it however you wish, as long as you credit both me and Jon Hicks. Oh, and you can't sell it.
To install and use Lucidica with Safari, make sure you've updated to the latest version. Then, after enabling extensions, just download and install the Safari version. Chrome users can simply click their link above, or install Lucidica from the Chrome extensions gallery. Firefox user? The Greasemonkey add-on will fit you perfectly. Fluid comes with built-in support for userscripts.