I know that it has a thousand uses.  If I understand correctly, the soldiers that are using them in the field stuff them with everything from rope to MRE entrees!  I have a couple of them that Gene sent to me to check out.

An interesting tidbit is that (if memory serves) it was originally just part of the Denali/Silverthrone rigs.  However, so many of the guys were removing them and sticking them on their first lines that Gene said the hell with it and starting producing them as a separate item.