Take your top 20 artists. For each of these artists, collect the top 5 similar artists. The resulting number of unique artists is your eclectic score. If the score is small (extreme = 5) your musical preferences are very limited, and if it is large (larger than 80, extreme = 100), then you have an eclectic musical preference. You can compute your own score at http://anthony.liekens.net/pub/scripts/last.fm/eclectic.php
My eclectic score is currently
91/100
The 91 related artists for my profile are ABC, AFI, Accessory, Altered Images, Amduscia, And One, Angels & Agony, Aztec Camera, Belle and Sebastian, Bryan Adams, Coldplay…