Dezinerfolio has some freebies section on their site. Here you can find the On-stage iconset, free icons for commercial use.
Unlike other free sets, this one contains the psd files too.
Here is the original post.
Midtone design studio provides this set of icons free for use in any project.
Even if it is a little offtopic, I want to say that I really like the design of this site. Midtone Design Studio belongs to Jonatan Castro Fernández, a spanish freelance graphic and interface designer who lives in Ourense, Spain.
I love these icons from Midtone too – they are free.