A high quality MP3 encoder
Multi-Format Audio-Encoder Front-end
winLAME is an easy to use encoder for many audio formats, e.g. MP3.
Drag'n'Drop GUI for LAME MP3 compressor (and similar commandline ones)
Command-line mass conversion of any directory tree of audio files.
Perl Script to Encode Sound Files
Easy to use shell script for batch conversion MP3 files to AAC+
Automating Powerpoint WAV Narration conversion to MP3 Narration