The Solar Vintage Brooch by Lost Values deftly marries the old and new, fusing newfangled solar-charged technology with the time-honored tradition of handcrafting. Conceptualized by Elena Corchero, founder and director of the Scottish design firm, the clover-like brooch is furnished with solar cells and LEDs, as well as temperature and movement sensors. The result: A winsome piece of high-tech style that charges itself in the day, then emits a subtle, ambient glow at night.
Wow, very cool!
For folks that are technically/DIY inclined you can make your own! There is a really great article on how make a solar powered bracelet or piece of jewelry on the Make Magazine site.
First Page:
http://www.make-digital.com/make/vol19/?pg=119
Second Page:
http://www.make-digital.com/make/vol19/?pg=120
And also a related video on the basic concept of the circuit.
http://blog.makezine.com/archive/2007/11/make_a_joule_thief_weeken_1.html