Find replace plugin by Bas Bosman and Ramon Fincken lets you find and replace text in pages, posts and trashed items with a GUI. Optional: postmeta and low_priority updates.
Current version 1.1.1 Requires WordPress Version: 2.0.2 or higher Compatible up to: 3.0.3 Last Updated: 2010-12-17.
Download: http://wordpress.org/extend/plugins/find-replace/