Yesterday I installed a new icon theme in gnome. I'm very happy with it.
I don't normally play around with icons, yet I've been having trouble looking at the Ubuntu orange all the time. This is a very nice change.
The theme is called: AER-OS-XK. It's 58.96 MB. You can download it at gnome-look here: AER-OS-XK
Installing the theme
First download it. Now open Theme preferences (in Ubuntu click on: System / Preferences / Theme). In Theme preferences click the Customise Button on the right.
Icons tab at the top. Then click install, navigate to where you downloaded the AER-OS-XK.tar.bz2, and select it.
It will take a long time to install, as there are many icons. Yet I think it is worth it. I'm enjoying using them. I hope you do too.