Im working is this useful tool for batch downloading albums of coppermine. With this tool you can easily download full galleries, check the videos:
single album
http://www.youtube.com/watch?v=heZyYbevHwU
multiple albums (can easily download full gallery with this method)
http://www.youtube.com/watch?v=_e4rHWwbPhI
Looks promising. There will be a lot of users who will find it very usefull. I can see some users though will not want to see their gallery leeched that way. Do you plan to implement a token that site owners could add to their site (a record in robots.txt or some meta tag) that will stop your tool from downloading from a particular gallery?
Anyway, we'd like to see your contribution here once you have finished your app.