Yesterday Yahoo! release of a library of design patterns (think “best practices” for web interaction designers, though “design patterns” have a long history in software engineering) under the Creative Commons Attribution 2.5 license.
See the Rate An Object pattern for example. The “object” used in the example is a restaurant, but could be anything, say a remix (if you’re logged into ccMixter you’ll see a ratings UI very similar to the suggested Yahoo! pattern).
Yahoo! also released a UI library of code that can be used to implement such patterns under the liberal BSD software license.