We dig multi-talented tools whose one function can be applied in many ways. Polyacrylamide crystals can “only” absorb 400 times their weight in water, but keeping your lawn wet is just one way they can make your life better. Here’s another great application: Sew a handful of the crystals into a scarf, soak it, and let the evaporation keep you cool.
Even under less-than-ideal conditions — say the crystals only absorb ten times their weight — an ounce of the crystals would absorb ten ounces of water, for a fair amount of cooling evaporation. Kafka Design makes Kool Ties in a huge variety of patterns, for $10 apiece. A “disposable” version runs $3 — for nasty-dirty environments?