I'm a big fan of Hydro'74 for Years now!!! This guy really makes some sick graphics.
Check out his site and I'm sure you will be blown away with his work aswell.
http://www.hydro74.com/

His blog: http://hydro74.wordpress.com/2007/03/15/free-vector-v3/

The other blog I was brabblin about is from a guy who works together with Hydro'74. Check out his shit at :

http://www.youaresolastyear.com/

There's a link to his weblog. Go download those free vector files. ;-) I did.