So I've seen this out there and it just appeals to my inner geek.  A binary counting machine made of wood.

So here a few other cool base two numbering system fun-ness!

Binary Finger Counting: [linky]

And what is up with that Hexidecimal (base 16) thing anyways.

How does binary relate to hexadecimal? Each digit of a hexadecimal number represents exactly four digits of a binary number. This property is due to the fact that 16 equals 2⁴. Manual conversion between binary and hexadecimal is easy: all you have to do is substitute one hex digit for every four binary digits, or vice versa. See the figure below.

While binary is easy for computers, enormous strings of ones and zeros are a bit unwieldy for people to use. However, as we saw in the preceding section, hex numbers are significantly shorter than their binary equivalents. Because of the simple interchangeability of binary and hexadecimal, humans can read digital data in hex, which preserves the underlying binary format that computers use, while presenting the information in a more human-readable format.

Read More about that here: [Hex Headquarters]

How about a Binary Clock.  Spend more time decyphering the time of day than actually doing something productive. [linky]