I've been using command+spacebar for basic calculaions since Leopard. In Australia the service charge is built into the cost of the purchase so us Aussies rarely get much practice tipping. When I travelled in the US last year I found Tipulator quite helpful. Its particularly good that you can round the tip to the nearest palindrome so that when you review your bank statement it is blatantly obvious if someone took a larger tip from your card than you had signed for.
10/20/11 at 4:22pm