Ubuntu 1304 Sushi
Sushi is a file previewing program, activated by highlighting the file, then hitting the space bar. You can close by either Escape or hitting the X. This program lets you listen to audio files, watch video files or picture files. You can also look at HTML and TXT files. It will not open Libreoffice/Openoffice files or EPUB/MOBI files. It opens PDF files, but very slowly.