Forza Decal Browser v0.8
ForzaCustoms.info

From http://forums.xbox-scene.com/index.php?showtopic=448052:

Right now it simply allows you to browse the TGA files in a directory where you have extracted them using ForzaBinDump.exe Transparency is supported by the browser. You can even change the background color of the full size image. (ONLY for viewing purposes.) I still have a lot of ideas and plans for this project and it will ultimately be MORE than just a decal browser.

Usage:
  1) Copy your ‘decals.bin’ file from your Forza Game Disk.
  2) Extract TGA files with ForzaBinDump from ForzaCustoms.info
  3) Open containing folder with Forza Decal Browser.

Have fun!