The best multipurpose tool I've discovered so far is the Cobrahead Weeder.
http://www.cobraheadllc.com/pr...
As long as you keep the head wickedly sharp, it's a Godsend. Can't get up & walk to a weed up in a raised bed? No problem. Need to surgically excise a weed growing next to a prized plant? Done. Have clay soil that needs to be broken up? Piece of cake. Got aggressive roots reaching into areas where they don't belong? Sayonara. Got a compost pile that needs aeration? Can do. Have some compost scattered on the ground that you want to incorporate into the soil? Easy. Can't reach a tool you dropped? You can now.
The long-handled version comes in three lengths, and it's very light. That makes it easy on your arms & shoulders, and the leverage it gives you can really help multiply the force you apply. I don't know what magical alloy they use to make the steel head, but it's indestructible. It's strong but not brittle, and holds an edge well.
As long as you keep it super sharp, it'll make gardening sooooo much easier.
