Image Viewers and Editors that handle RAW images
I have two photo viewer and basic editors that handle RAW images. They are both free.
1. Geeqie, which is a fork from the now undeveloped GQViewer (not since 2006). It handles higher level requirements including exif data for the most popular RAW digital camera formats. This is in the Ubuntu repos and is on sourceforge at: http://geeqie.sourceforge.net/. One very nice feature is the ability to click a link to gimp and other editors you have listed in your graphics menu. this is a nice touch.
2. Fottox, which is in the GetDeb repos and on its own site. This too, does good basic picture editing. Fottox is at: http://kornelix.squarespace.com/fotoxx/
These are both good additions to the package library for the digital photographer.