Last week I showed a simple way to upload files to your iPad for use with GoodReader and iBooks. Well, the good people at GoodReader have added a simple USB solution, so that you don't even need to open iTunes. GoodReaderUSB.app is available (For free! Free is good!) for both Mac and WIndows.
Connect your iPad or iPhone, launch the application, drag and drop. It's that simple. And yes, if you have folders set up on your iPad, you can drop to specific folders. Easy.