over the weekend, I managed to make a knock off of CB2's pebble mat. :)
I purchased the rocks and a carpet square at the dollar store. I bought the glue at Home Depot. Total I spent around $14. Not too bad. :)
The rocks kind of fell in place like a child's puzzle. It was extremely easy to do. I used a few different versions of glue. One epoxy type set extremely quickly, so I had to rush to get the rocks in place. The other took hours before it actually set.
In "real life" the mat looks a lot darker in color. Closer to CB2's. (more like the color of the rocks above, in the bags.)
Be warned- this thing is heavy!!