Does anyone know of a good set of of open source icons? I am currently using the Boomy multiplatform set, but it's rather limited.

Otherwise, I know about the Silk icon set, but they are only 16x16 and somewhat dated (2006!). There is also the Tango library, the Open Icon Library which I find to be a mess, and the Faenza library which I have just found and which seems quite nice.

Anyway, any other icon set that I should be aware of?