Here's an interesting puzzle.
This is called "Rudenko's Disk" (Brainwright) — finding information or solves for it online isn't all that challenging, which would largely ruin the fun here, so don't go looking it up. Here's what the puzzle looks like:
The puzzle consists of 7 movable Dots, colored roughly Red, Orange, Yellow, Green, Cyan, Blue, and Pink. In the picture they are in the middle, in the order listed, starting at the bottom right and running clockwise around the center circle (which does not move). These Dots are in a track which runs around the center, counter-clockwise from where the Pink Dot sits, around the center circle to where the Red Dot sits, then branches off in both directions to form the two visible track arms at the upper and lower extremities of the puzzle. Each of these arms runs through a series of colored positions, also ranging through the same set of colors in the same order (Red, ..., Pink). The two arms are completely symmetric. Though not visible with the Dots in their current position, the Dots on the center track are also sitting on like-colored positions - Red Dot on Red, ..., Pink Dot on Pink.
The colors' order is important. Looking at the right-hand part of the puzzle, at the "Y" where the three sections of the track meet, each colored Dot can only move as far down any of the three track parts as their own color. Thus, the Red Dot cannot move beyond the Red position (so can never be farther from the "Y" than it is right now, regardless of which section track it is on). The Green Dot can move halfway along any of the three track sections, but not beyond there. The Pink Dot can move to any position on any of the track sections.
Two final notes. First: if they are pushed as far down the track as possible, the Dots will sit exactly on their own colored position. And second: in practical terms, only one Dot can be inside the "Y" at a time - that is to say, for a Dot to traverse through the "Y" from one track onto another, any Dots on the third track must be pushed all the way to (or beyond) the Red position.
Ok - now that all the mechanical considerations are covered, hopefully intelligibly, on to the objective.
How many Dot moves will it take to move all 7 Dots from their current positions on the center track to their appropriate positions on the upper track?