Glance is an Eclipse plug-in providing extensible useful incremental text search in Eclipse. This plug-in support following features:

• highlight all found matches
• background search which never blocks text box
• search in tables and trees
• update matches when target content changed
• new text containers can be supported through extension points
• a lot of search settings

Just press CTRL+ALT+F (COMMAND+Option+F on MacOS) in a text area.

http://code.google.com/p/eclipse-glance/