I want to update my site with a plogger gallery but it will take some time to make it the way I want. I do not want to take my current site down. Is it possible to install plogger in a temporary directory and copy all files to the root when everything is ready?
There may be a problem with moving images you've uploaded, on some servers Plogger sets the owner of modified files to "Apache" or "www-data". If that is the case, you may have trouble moving the files with your ordinary web FTP user.
Otherwise, it shouldn't be a problem, just install it in a subfolder. When you want to move everything, just do it normally as you would via FTP. The one thing you would have to change it the value of "Gallery URL" in the options menu. Other than that, and mabye a refresh of your .htaccess file, it should be straight forward.