Use Gimp for editing Terrain Heightmaps

Ive seen this issue around on the forums many times, and it has also effected me. I use Gimp for image editing, however, only the 8bit .raw hightmap from Unity can be opened/saved from Gimp. If you want the detail of 16bit, you can't use Gimp.

Until now!
I found this after Googling for some time, I do not take credit for this piece of software, but recommend it immensely!
http://dubaron.com/terrainconvert/

Usage:
1) export the terrain heightmap from Unity at 8bit or 16bit, Byte order does not matter!
2) drag-drop the exported terrain.raw onto the EXE from the download, it will automatically detect setting and convert the file.
3) Open the converted terrain.raw.tga in Gimp, then do Image -> Transform -> Flip Vertically.
4) Edit the image to your liking (its not greyscale, and only the Red channel is converted).
5) Flip the image vertically again (Image -> Transform -> Flip Vertically)
6) Save/Export the edited terrain.raw.tga
7) Drag-drop the exported file onto the EXE again, and it will convert to terrain.raw.tga.raw
8) Import the heightmap into Unity, and it will auto-detect the settings!

(flipping vertically makes the image have the Z axis facing the top, so "North" is up)