I'd like to move all of the contents of 40 folders to 1 folder. Rather than doing this 1 image at a time in the admin front end, I'd like to :

1. Run Clear Image Cache
2. FTP copy all of the images to the new folder
3. MySql update the images table with the new albumid (folder) value.

Does this plan sound feasible? Has anyone else done this?

Zenphoto is filesystem-based, so you should be able to simply move the images from one folder to another. Then you can refresh the database and everything should be fine.

If you have database data for the images (descriptions, etc.) that is not physically in the image metadata, then you will need to update the album ID of the image records.