As already mentioned, 'foo' and 'bar' come from FUBAR, an Americanization that seemed popular during World War II. Apparently the British were already using U/S for marking 'unserviceable' equipment, but that didn't go down well with the United States. I've also remember seeing 'NFG' on bad EPROM chips when I started working at Motorola in the summer of 1981.

My pal Bob from Burlington once told me that 'foo' came from 'for once only' -- as in, something that you were going to build once and forget. I don't know where 'baz' came from, although I have a friend Mark who is nicknamed 'Baz' -- it's a short form of his last name.

The word sometimes used as a fourth in that group is 'quux', and I'm curious about that one too -- it always makes me think of 'quincux', the name for an arrangement of five items placed in a cross (one in the middle, one above, one below, one to the left and one to the right). It's also a terrific book (so I'm told) written by a first time authour who wrote just a page each night without telling a soul .. but I digress .. as usual ..