IntelliJ CodeSearch is a powerful add-in to JBuilder delivering sophisticated usage-oriented searches to Java developers. 
This kind of search allows quickly finding different types of code dependencies such as class inheritance, method calls and other program element usages. It significantly differs from the regular text-based search because it correctly distinguishes program code, comments and strings and quickly gives you the most complete information about the program element usages. 
This technique can be used for different types of program navigation, code learning, refactoring and so on. 

IntelliJ CodeSearch web page: http://www.intellij.com/products/codesearch/