Aha! Use: Decoration and insulation for potted houseplants. Cover soil with polished stones or river rocks to prevent cats and dogs from digging and to keep the dirt moist. If you don't live near a riverbed or gardening store, try Zen Rocks from Smith & Hawken ($10 for two pounds, www.smithandhawken.com).
Reward: Fewer dead leaves and pet mishaps.
Other Use: Line soap dishes with stones so soap doesn't get mucky.