What's in your art kit?

On the "Maken Art" blog, the question was posed.. What is in your kit? 

I carry entirely too many art supplies daily.  I usually tote around a full backpack of various items to entertain me throughout the day.

Shown here is what I usually have on hand:

• 1 or 2 sketchbooks with a few different types of paper inserted throughout
• Cigar box of ~80 assorted Prismacolor Pencils
• Prismacolor fine line markers .005-.8
• Grey set of brush tip pens
• Glue stick & tape
• Scissors
• Prismacolor blender markers
• Copic 12 pc set of Cool Grey .Too Markers
• Zig Pigment Ink Markers .05 in a handful of colors
• A couple of different mechanical pencils
• Mini electric eraser
• 2 clear flexible rullers
• Retractable X-acto knife
• Creatacolor 12 pc Graphit Selection
•  Erasers and sharpener
• Sharpie Marker and Pen

I almost always have these items with me. Tee hee. Because you really never know when that inspiration will hit. Occasionally a few items will be swapped out for others such as watercolor or inking supplies but I try to only use those at home for convenience.  What are your essentials??