Good free DWG viewer for Mac OS X

I developed ImageBank for iOS to do exactly this - streams photos from your PC/Mac to your iPhone, iPad or iPod Touch. It's universal so it works natively on the iPad, and it even works over 3G.

There's a free version too if you want to try it out: ImageBank Lite

It's only US $0.99 to buy or upgrade from the free version.

Microsoft has an official OneNote for iOS on the App Store. It was free for a limited time when I got it. It is still buggy, but should get better as it is the official app. As far as the other Office file types, I know of an app called Documents To Go. I cannot officially recommend it since I do not own it. I just know it's out there and that it supposedly allows you to open and edit Office files. You may want to check it out.

I do agree with David's answer in that if you just need to open these files, Dropbox is a very decent solution. I use Dropbox to open files I create at home using Pages and Numbers (I do not use Office, but if I did I would still use Dropbox to open the files I had created on my iPhone). Dropbox will not allow you to edit the files, but to quickly open while on-the-go it is a very good solution. Good luck.