It's a fantastic tool to do easily all boring text operations!
Heytools - JavaScript tools, AJAX tools and some fully server side tools.
KeywordDensityTool.net - Keyword Density Tool
NimbleText - NimbleText is a text manipulation and code generation tool available online or as a free download.
KeywordDensityAnalyzer.com - Website Keyword Density Analyzer Tool
TextPipe - Search and Replace, Find and Replace, Web Sites, Database Extracts, XML, CSV, Tab, mainframe COBOL data and more
WordCounter.net - Count words, sentences, paragraphs etc.