Via 37 Signals I see that Forbes has an interesting article called The 20 Most Important Tools Ever. In terms of human cultural development, cruise their list and see if you agree with the tools listed. I’d think a shovel would beat out the chisel and we never would have had metal working (for the rifle #7 et al) without the bellows used in the blacksmith’s forge. The hammer is also not on the list. Friends will be happy to note that the needle is 13th.