I Guess If You Are An Outdoor Type,

a mobile telephone case like this one will make a lot of sense,

the TaskOne G3, has a multitude of handy tools and gizmo's that you might need for a week or two in the jungle or wilderness such as, 

• 2.5" Knife with serrations
• 1.8" sawblade
• Pliers with wire cutters and 3-6mm Hex screw cutouts
• 5" ruler (1/8" graduations)
• 6 Allen wrenches (1/16", 2.5, 3, 4, 5, 6mm)
• Dual spoke wrenches
• Wire stripper
• Small and large flathead screwdrivers
• Phillips screwdriver
• Universal reciprocating saw-blade mount
• Dual landscape and portrait kickstands
• Bottle opener,
• 
  

all useful stuff, but there is no mention of a solar battery charger, which if you get lost could more important than all of the above!