Another idea to come out of the USA(who says that the USA don't make anything anymore?)

Its a bracelet made from tennis string, and held together with a magnetic clasp.

The multi-colored bracelet measures slightly less than 8 inches around and comes in two styles: a three-strand version that weighs 2.5 grams and costs $4.95, and a four-strand version that weighs 3 grams and costs $5.50.

The Stringlet is currently available in 12 different color combinations. A new set of colors will debut next month, including red, white and blue and metallic versions, bringing the total to 20 different varieties, with team names and simple slogans planned for the future. Its creator envisions the Stringlet someday serving the same role as martial arts belts, with different colors corresponding to advancing skill levels.

To find out more, click the tenniszoo link.