AcidSearch is a search enhancement for Safari. It adds unlimited "Search Channels" to the Google search field. Channels can be customized in a nearly infinite variety of ways. AcidSearch also includes powerful features such as JavaScript support, the ability to import iSeek and Butler Search Sites, true hierarchical menu organization, and the ability to search multiple search engines at the same time. AcidSearch also allows you to access your search channels with key equivalents, shortcuts (a la SafariKeywords), and a contextual menu.

Requirements:
OS X 10.4-10.6
Safari 3, SIMBL or PlugSuit
Universal Binary