I don't mean to beat a dead horse but the OP's question of copying one folder is exactly what I want to do. I have been using SD since May 2005 but mainly for making a bootable disk. I know this is the function of SD. But I have a very large DevonThink DB in a folder in my document file on my boot drive that I would like to copy to another drive. I have a MBP that has a 2nd drive (pulled out the CDROM). The 2nd drive has a dropbox folder and this is were I want to copy the file. You may ask why not just use dropbox. I don't know the technical details but Devon seems to think that it is easy to corrupt a DevonThink DB using dropbox. I think they have a beta sync app in progress, but I don't want it use it yet until they get it right. This DB is 3 years old and my life is inside it!
Thanks
Joe