NewTux Flash Tools.... they allow you to edit the image in something that looks similar to windows explorer. You drag and drop the files into the image, and then click the save icon.
After you click the save icon, the program will then freeze and say "(not responding)". Dont be fooled. Wait 2 minutes and it will come back to life, and your new image is then ready to be flashed.
NewTux Flash Tools is in the downloads section.
Liam.