A site you may all want to check out is Icon Archive
They host a lot of icon sets for different operating systems, all of which are free, and often supported directly by the artists who put them together. Just a really smart place to find icons.
Lets face it, Windows has particularly poor icons for most devices - Plug in your phone ... Oh... Alright, it looks like another Hard Disk - So this is a great place to go to pick up something to freshen up your devices and desktop!
Here's a few great sets which you should go check out:
App Icons by Arrioch - LINK
Rabbit Xp Icons by Flameia Design - LINK
Japanicons Icons by ZaKaR - LINK
Orbz Icons by Arrioch - LINK
Some of the sets out there look really great, and trust me make it a little more tolerable browsing around your computer!
Happy browsing guys, hope you find something you like :)