Searching for a solution to Apple's stupid iTunes policy on uploading files from iPod or iPhone or iPad, I've found another application: PhotoShare. This application allows one to directly share pictures between your i-Device, other i-Devices, and any desktop computer. It's pretty straightforward to use, and works well - for pictures. It doesn't enable sharing movies, for some reason. Scratches head.
Run the application on your i-Device and a few destination choices come up: Facebook, Flikr, Picasa, Twitter, "Computer" and "WiFi".
You can upload pictures to those services and obviously would require that you log into an account in one of those services. Since Twitter doesn't have an image storing service the Twitter choice probably works with a service like twitpic, doing an upload to some 3rd party service which then does the tweet.
Sharing with a desktop computer is pretty straight-forward. When "Computer" is chosen it tells you a URL that you're to visit with your desktop computer. You select pictures from the Camera Roll or other pictures stored on the device. Go to the designated URL and the browser shows the selected pictures, plus it allows transfer of pictures from the computer onto the i-Device. From this screen it's easy to select pictures to exchange from computer to i-Device, or from i-Device to computer.
I did not check the WiFi choice.
The application works pretty well and does not compress the images. Some applications of this sort do image compression which can introduce loss of precision. However for me there is a massive flaw - it does not support transferring movie files. This is pretty darned puzzling. The camera application puts both movies and photos into the same camera roll, and PhotoShare allows selecting from that camera roll, but it doesn't offer the ability to choose movie files. Why?