Monsoon has posted a couple of video tutorials on making rocks and rock structures with Metablobs in Vue 7 Infinite. Here's what Mark has to say about the technique...
It is a pure and simple joy to use metablobs and displacements without freezing and crashing. I had stopped even trying to use them in V6. This V7 is feeling very very nice indeed!!
I make a series of custom shaped primitives and save them as .vobs. Long rectangles, flattened cylinders, wide and flat or tall and thin etc. Then just load, duplicate, twirl and blob.