A treasure trove of rarities, oddities and tech "firsts" has been brought together -- including an experimental 17th century mechanical calculator, a 108-year-old telephone and an incredibly rare, headline-grabbing Apple 1 computer -- to be sold at auction Friday in Cologne, Germany.

Forbes has released its annual list of the 100 top female politicians, CEOs, activists, celebrities and philanthropists who matter most. Here's a look at the world's most powerful women of 2013.

Kick your metabolism into high gear with these 27 tips.