It's always interesting to compare two search engines. Some people say Yahoo Search is almost as good as Google Search, others say they show similar results. There are many sites that compare the results provided by the two search engines.
My favorite site is Google vs Yahoo, that uses Flash to compare the first 100 results.
GahooYoogle splits the screen in half and lets you compare the results for web search, image search, video search, news and shopping.
If you want to compare Google Maps with Yahoo Maps, Sergey Chernyshev's site is helpful. You'll notice that Google Maps' satellite imagery is better, especially in Europe.
Consistency vs innovation