I've been using a search tool for the last year or so that I absolutely love. Goosh is an Ajax tool that behaves like a *nix shell. You can find and use this tool at goosh.org.

Favorite features:

• No ads.
• Quick readable results.
• Wikipedia search.
• Superior image search.
• Firefox search integration.

Tips:

• Type "help" at prompt for all commands.
• Type "addengine" at prompt for Firefox integration.
• Use tab complete for related searches.
• Use the alternate search keywords, by using the keyword followed by your search string. Here are some examples:
  
  1. > i test
  2. > p corvallis oregon
  3. > t english spanish test

I haven't looked closely into what configuration options that are available. I think having color themes would be nice.