I stole this from someone's journal
Go to the page of your number one artist (or of the week) and follow the link of its number one similar artist. Repeat that for this artist and so on, noting each artist as you go. Do this until you've got 50 artists (not including your number one). If you get any repeats, just go to the second similar artist or the nearest one that you haven't already listed.
1 The Decemberists
2 Sufjan Stevens
3 Iron & Wine
4 The Shins
5 Death Cab for Cutie
6 The Postal Service
7 Bright…