Drag and Drop
Granted your drivers installed correctly (mine tried to find 3 different drivers and failed one), your Nexus should read on Windows 7 like a media device. You can open it up and drag and drop files, just like you would if your SD card was mounted. Don't know why people are having so many issues with this, but I've put it here to let you know it IS possible. I've already sideloaded a few apps this way, as well as transferred my picture albums.