Aiseesoft iPad Manager for Mac is a very complete management tool. It can be used to transfer content from your iPad to your Mac and vice versa, and from your iPad to other iOS devices directly. The app also comes with both a video converter and a DVD ripper. These tools allow you to convert your media and transfer it to your iOS device all from within the same application. This makes the process easier and faster.
I tested this application with an iPhone 4 instead of an iPad, and it worked like a charm. So you may also be able to use your iPod Touch with it. When you connect a compatible device, it will be listed on the left side of the window, and under its name, you will see a list of types of files that you can transfer. When you click on one of these, the pane on the right part of the screen will show all the files of that type that your iOS device holds. You can then check those that you want to transfer. If you want to put content on your device, you can simply click on the "Import files" button and select the files that you want to copy. If you select a video file that is not supported by iOS devices, it will go through the built-in video converter first.
There are two versions of this app: Standard and Ultimate. They are almost identical, with the exception that the Standard version limits the types of content that you can move between your Mac and your iOS device, and it doesn't have some extra edition features.