Add images to Gallery directly from your desktop computer, e.g. per drag and drop from MS Windows Explorer.
Security Warning: Users of Gallery 2.2/2.2.1/2.2.2 should upgrade their WebDAV module via Site Admin -> Plugins -> Get More Plugins. Critical security vulnerabilities have been fixed in Gallery 2.2.3 with WebDAV module version 184.108.40.206 of the 1.0.0 series and 1.0.4.
Note: A bug sneaked into Gallery 2.2.3's WebDAV module (version 220.127.116.11). Your WebDAV client would list all items of your Gallery in a single folder/album instead of listing just the direct children / sub-albums. Please update your WebDAV module via Site Admin -> Plugins -> Get More Plugins to fix this odd behavior.
Mount Gallery on your desktop. You should be able to get directory listings, drag and drop photos and albums, and update photo and album properties with your operating system's native interface, or with a WebDAV client.
Some clients that work and some that don't: http://galleryproject.org/node/104831