We have a visceral reaction every time we think about the fact that it's the year 2012, and women still make about 20% less than men do. So, when a business executive, new mom, and brilliant woman-on-top was appointed to a top corporate position a few months back, we took notice. A lot of notice. Truth is, we haven't stopped thinking about Marissa Mayer since she was named CEO of Yahoo, and not just because her hefty payday is a sign that women may finally come to earn the same as men for doing the same jobs.Making an annual salary of $1 million, plus a hefty bonus, and an impressive stake in the struggling company, Mayer isn't quite a billionaire yet, but we're intrigued by her potential to get there. And with the number of female billionaires out there still feeling like a small and exclusive club, the big-deal appointment made us start thinking about all the other women out there who have reached their goals, and made it big in their own ways. These billionaires are stylish, smart, business-savvy, and representative of a diverse array of background and interests, but the one thing they've all got in common? They're all very, very hard-working, inspiring women. From a handful of ladies who turned ideas into mega-retailers at the mall to the ones whose contributions save lives on a daily basis, these role models are proving you can be philanthropic, family-oriented, and ambitious (and no, that isn't a dirty word), all while being a well-dressed, well-spoken woman. These luminaries, COOs, co-founders, and entrepreneurs have chipped away at that glass ceiling for all of us — and some are even threatening to shatter it completely. Whether you're about to start your first day of work, thinking about leaving to pursue another dream, or trying to grab onto the next notch on the corporate ladder, peek through this list of extraordinary women first, and take heed of their admirable career advice.