White Olive Icon Collection
50 icons in PSD, AI and as a .tff font set.
White Olive Icon Collection is a free Icon design resource made by Dribbble user Breezi. As far as I can tell, its license is Creative Commons Attribution.
Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.