Twingine allows you to search Google and Yahoo at the same time.

The way results are displayed needs some work but it has possibilites.

What would be cool is to mix the two results into a single resultant set that identifies if it is a Google or Yahoo result. You would have to come up with a way to give more weight to one result over another to know how to re-order the results…

Check out these posts too:

  1. Visually compare search results between Yahoo! and Google.
  2. Instant search from Yahoo!
  3. Search engine results with thumbnails
  4. Search engine roundup
  5. Google search results includes movie trailers
  6. The future of search engines is in beta now
  7. Breakdown of a Google search result