DanRabbit and The Elementary Project ([link]
) are quite popular these days; unfortunately the icons are Gnome specific.
Technically Gnome icons should work under KDE (yay freedesktop) and they do for the most part, but there are some oddities that each DE uses.
Here is my very preliminary, very crude port to KDE. Lets hope The Elementary Project does an official port.
I believe these are under the GPL but I could be wrong; if I am in the wrong please leave me a message.