Knots

Also if you know how to clove, youll remember very easily how to munter … Which is a critical skill on multipitch

Yep, when tied on a carabiner the similarities are very obvious.

For a clove hitch around anything larger in diameter I'd agree with Richard and wouldn't trust it. But after mulling the question over I thought I'd grab some rope and arrange some scenarios. (Safety Disclaimer: I don't climb much, don't trust a word of this post, etc., etc.)

1. A standard clove hitch on a locked carabiner:

2. Here I deliberately loosened and arranged a clove hitch on a non-locking carabiner (yes, a sharp tug did exactly what you'd expect):

3. Finally, a clove hitch tied around a larger diameter object (in contrast to the first image):

Additional refs:
http://www.geir.com/mythbuster.html (item 4)
http://www.lightandmatter.com/article/knots.html

"I am so glad I learned how to properly tie my shoes at the early age of 62. I wonder how I made it through all these years and am alive to talk about it :)"

Velcro?

"Can't people do a classic over-the-shoulder abseil any more?"

They could, if they had been trained. That was one thing that I demonstrated and taught in the summer of 1971. Unfortunately, it does a number on your clothing. All sorts of strange wear patterns show up in strange places.

–B.G.–