This is the easiest way I've found to get pictures from the gallery here and elsewhere to my Droid. You will need to be using Firefox on your desktop or notebook and the barcode scanner app on your Droid.
Install the "Mobile Barcoder" add-on for Firefox and start surfing. I love my Droid but, obviously, it's easier to surf the web on my desktop. When you find an image or link you want on your Droid, right-click on the link or image or place your cursor over the "Mobile Barcoder" icon (squares on bottom-right of screen) and it will create the QR code for the link or image.
Then you just scan the code with your Droid and, voila, your Droid goes right there. You can download and save the image with a long-press on the image. I found this out after numerous wallpaper downloads to my desktop and USB transfers. Uggh. This is so much easier and quicker unless you are downloading images by the hundreds.