I was visiting another site's bbs and found a post about Ezy-Rock. It's a company that is selling instructional videos on how to make authentic looking rocks from basic concrete and wire mesh or hard refuse.
Has anyone seen these videos and used them successfully?
I tried going that route and finally took a little shortcut and saved a lot of time, trouble and money. I found rocks and boulders that only weighed about ten pounds. They worked great and look like the real mccoy. Go to: http://www.patioandlawn.com and check out their rocks.