GImageView is a GTK+ based image viewer which supports tabbed browsing, thumbnail table views, directory tree views and drag and drop. It also support movies using the Xine library and MPlayer, and supports images in compressed archive formats.
DuMP3 is a duplicate and similar file finder. It finds exact duplicate binaries by hash, similar text files by substring content, images (JPG, BMP, GIF, PNG, etc) by color and audio files (MP3, WAV, OGG, etc) by wave data. Future: fonts, video.