Concrete blocks are fantastic, but not always practical. Plus, they don't travel well. A better alternative is this rugged, water-filled bag. Full, it can anchor garden netting, plant protectors, shade tents and more. Or take it camping to weigh down tents and shelters in windy conditions. The large carrying handle also doubles as a handy tie-down. When you're done, simply pour the water out and fold the bag flat — try doing that with a block of stone!