As I said in the sierrachart bridge thread, I'm keeping a kind of mirror of all mtgoxusd data in my dropbox, with data segregated in daily files, e.g.
https://dl.dropboxusercontent.com/u/24587684/mtgox-daily/2013/04/23. It goes back to 2010/08/17. It's automatically updated every 90 minutes, although since the process goes through my laptop, some updates will be skipped while I'm on the road.