Above is a very recent photo taken of some new sandbags (SBs). One is a 60# and one is a 40#. The 53# KB is shown for scale. These SBs are made out of sand and truck tire tubes. They seem to be very durable. The 40# has a nylon strap running through the section of tube to create handles. Surprisingly, these SBs are extremely ergonomic....well, as ergonomic as a 60# bag of sand on your shoulders can be. The curvature of the SB creates a yoke-type fit on the traps and neck. These are absolutely ideal for running or trekking under load during workouts.
These are Nate's. He says he's got more tire tubing for those of us who want to make some at home.