I just discovered a pretty neat little trick. I had to accompany my wife to the mall this
weekend and a kitchen store was on the list. There was this interesting display of "rubber" jar
openers. The type you drape over the lid and crunch down on with your hand and it sort of
conforms to the lid shape thus making it easy to unscrew. Well that sucker had about maybe
400 little squares "cast" into it. A perfect mold for cobble stones. Just tried it out and it
worked fine! I dumped all of them in a cup and shook it for a few minutes so the sharp edges
would wear off a tad. Glue mold-face (perfect side) down and grout. Cost is about $8.00 for
a mold you won't wear out - ever!