Here is one of the weirder ways I've ever seen of solving the Rubik's Cube. C. J. Karr solves his cube while riding a bicycle! The camera operator is on a bicycle, also, so the solving itself can become impossible to see at some points, but it does make for some interesting and dynamic shots.

It looks like Tony Fisher may have some competition. Ryan Thompson has come up with Rubik's Cube-type puzzles in the shape of a cylinder, a hexagon and an octagon.

This anonymous Pi reciter, known only as idelwood's brother has the first 40 digits of Pi memorized. He should be careful, as this young child knows almost as many!

This is Dave Campbell. Dave, much like T. Wright and Macky, can solve the Rubik's Cube one-handed. However, Dave's one-handed solve is the fastest I've seen!

The complete lecture itself teaches how to improve your mental calculation skills, and is very clearly taught. These videos also came with audio tapes and a workbook, which are referred to in the videos. It's not hard to make up your own sample problems, however.

The above video is only the first of 11 parts. Here's an index for the complete set of Mathemagic video clips:

Part 1: Introduction, Adding 2- and 3-digit numbers Part 2: Adding 2- and 3-digit numbers, Calculating tips, Subtracting 2- and 3-digit numbers Part 3: Subtracting 2- and 3-digit numbers Part 4: Subtracting 2- and 3-digit numbers, Multiplying 2- and 3-digit numbers by 1-digit numbers Part 5: Multiplying 3-digit numbers by 1-digit numbers, Percentages, Division of 2- and 3-digit numbers by 1-digit numbers Part 6: Division of 3-digit numbers by 1-digit numbers Part 7: Multiplying fractions Part 8: Multiplying, Adding and subtracting fractions, Converting fractions to decimals Part 9: Converting fractions to decimals, Estimation, Squaring Part 10: Squaring, Algebra Part 11: Algebra, Fibonacci addition trick

Towards the end, there are a few times you are referred to the workbook for a more detailed explanation. Here are some links on the web that can give you the required explanations: