So cool. A node - graph browser that describes itself as “A visualisation tool for finding new music by exploring links between related artists”.
The Audioscrobbler Project is also very interesting:
n a nutshell, Audioscrobbler endeavours to be your personal music advisor. It grows to know what music you like by monitoring what songs you play on your computer. From this information you can discover other users that share some or all of your taste in music. You can also view data showing what your most-played artists are, and find out who likes a particular artist the most. Audioscrobbler makes it easy to find people with similar musical tastes, and allows you to browse their profiles. Automatic suggestion generation is currently under development.