Have you seen WPSeek? It’s most simply a search engine for WordPress developers and theme authors.
Here’s what you can find via their service:
- Results page
- Neat Auto-suggest that maps its content from anywhere within the function name
- Related Codex Documentation
- Code Snippets
- Top Google Search Results
- User discussions
- User Notes
- AJAXified results page; no need to reload page on any operation
What you’ll definitely want to check out though is their API which is not too shabby at all. It’s not perfect so don’t quote me on it being the be-all end-all search engine but it might be helpful for you in a variety of situations and usecases.
Check it out and let me know your thoughts.