Unicode Transmuter is a batch conversion utility for plain text files. You can add a
bunch of files from various places, and convert them from non-unicode encodings
Supported Encodings (first table)
Each file is copied to a 'unicode_files' directory, so you don't need to worry about potentially ruinning your files should something go wrong.
Download (It's free and open source)It's also in its very early stages, though more useable than this page.