Styles for grid-based layout, layout.css, (awesome), a comprehensive "browser reset", reset.css, with reasonable defaults for typography and spacing, typography.css. Also, some form styles and a good foundation for a print stylesheet. All in all, it's a great base.
Quick reference for Blueprint CSS.
A collection of independent, reusable Django apps: Basic Blog, Basic Places, Basic People, Basic Library, and Basic Profiles.
( via Reddit )
Flot, a newly announced plotting toolkit for use with jQuery. On a completely superficial level, the examples are nice looking!
( via Ajaxian )
In-depth articles on CSS, design, Javascript and other web development topics, with lots of great design showcases.
Examples of using Google Chart API, which looks super slick!