Better than MP3?

After disussing MP3 compression, the question was "is there anything better than MP3?" Looking for an answer turned up some new resources that show some of the many factors involved in compressing sound. First MP3: The Definitive Guide provides more information on MP3. ITunes uses Advanced Audio Coding (AAC). One of the factors in compression quality is how many bits are used to encode each second of sound. MP3 or AAC are not implemented in only one way. The bit rate can vary and the compression details can vary.

Some people that are obviously musically well-trained have done comparisons of MP3 with AAC. See REPORT ON THE RELATIVE QUALITY OF AAC AUDIO TO MP3 PART 1 which also tests the Ogg Vorbis format and mentions the LAME encoder for MP3.