The field knife/saw combo on the Sog Seal Revolver/Hunter Knife works well for me - its a very comfortable and agressive little hand-saw. http://www.sogknives.com/store/HREV-7.html


Ray Mear demonstrated a field-crafted buck saw in one of his vids - he packs a buck-saw blade and crafts the rest of the tool in the bush. Indestructibles has an example: How to Build an Ultralight Portable Buck Saw -
http://www.instructables.com/id/How-to-Build-an-Ultralight-Portable-Buck-Saw/