Tired of the bloated Coppermine Photo Gallery? The much lighter Zenphoto gallery script may be a good alternative.
The compressed download is under one megabyte, and the installation looks fairly simple. Just upload via FTP, and run the installation script.
The installed gallery is responsive and clean. Don’t take my word for it, though. Look at the demo gallery.
The script is fairly new, and is still evolving. Some features, like RSS support, have just been added.
If you need a gallery (for a design portfolio, to show off your photos, etc), then be sure to check-out Zenphoto.