Most search engines serve up search results in a list, one result below the other. A few, like Yippy, cluster the results into subtopics, but they're still linear and usually unrelated to one another.
Here are 2 interesting search tools that present your results in different ways.
Designed as a learning tool for students, instaGrok is useful for professionals as well. Results are displayed as a mind map, with interconnecting concepts. You can annotate and save your search as well. To get a better idea, watch this brief demo from the instaGrok team:
Ultimate Research Assistant
OK, the title may be a bit of an exaggeration. But this research assistant doesn't party late at night, never calls in sick, and is ready to serve you 24/7. The Ultimate Research Assistant extracts not only relevant links, but also text summaries from online documents, and presents them in a narrative "report."
For example, here's a partial screenshot of my query, psychotherapy vs medication:
Most of the results come from high-quality sources. Also, note in the menu at the top of the screenshot, that you can also display the results as a visual mind map and download an mp3 computer-generated audio of the results.
Don't toss Google just yet.
Think of the above tools as a way to begin your search. They help you narrow your focus. Then, take your refined concepts and search more specifically on Google, where you can limit your results to time lines, document types and other customizable parameters.
If this topic interests you, check out my post, Search Tips and Tricks for Finding Quality Content. (The Google Wonder Wheel mentioned in that blog post is now defunct. The tools on this page do essentially the same thing.)