This fun technique based on the 1x1 round tile with pin was sent to me by Richard. It's one of the the smallest inverted 180 snot you can achieve - beaten only by it's sibling technique. The piece has many hidden secrets, which you can check out in a post on The Rambling Brick - Richard's excellent blog.
To find the different pieces needed for this technique you can search LEGO's online Pick-a-Brick for the design ID's. We link other market places directly on each individual piece page, which you can find below.
Here's an example of this technique in action.