For many women in Silicon Valley, there was no chocolate or romance to be had on Valentine's Day. And that was just fine with them.

Women 2.0 hosted its annual conference Thursday, where 10 female founders battled it out in a start-up pitch competition for a meeting with investors and discounted business services. Here are five companies that stood out.

The company provides metered solar energy to the developing world, allowing customers to purchase energy for phones, lights, and devices on a pay-as-you-go basis. Its solar devices are embedded with a speaker and microphone combination and utilize tonal cues--much like the first telephones--to control activation and meter energy.

In her pitch, CEO Lesley Marincola dispelled myths of the "sad T.V. version" of Africa, emphasizing Angaza customers' investment in education and developing businesses in their area. Affordable, metered energy will help them to achieve these goals, she said. Though she was quick to explain that Angaza Design is a for-profit venture, and not a purely social enterprise.

The judges liked what they saw: Angaza took home first prize--an opportunity to meet with one of the lead partners at Andreessen Horowitz and angel investor Esther Dyson.

Picture this: In high foot-traffic locations, like airports and restaurants, high-definition billboard screens display adds targeted to nearby consumers based on their mobile apps and social media profiles--sort of like the personalized ads that pop up on your Web browser, but in real-life. Sounds like a sci-fi movie, right? Nope. These billboards, created by Enplug, already exist in over 10,000 locations.

And they make advertisements fun, according to CEO and co-founder Nanxi Liu. Enplug’s billboards are interactive, making consumer experience more like a conversation than a lecture.

Co-founder Tanya Menendez understands the difficulties that small business manufacturers face in the Internet age. Maker’s Row is an online platform intended to eliminate friction between designers and manufacturers in the factory-sourcing process. The site allows designers to source their manufacturing needs domestically--rather than overseas--and allows sometimes marketing-challenged manufacturers to display their product quality in a way that is accessible and transparent to potential clients.

Thuy Truong and her co-founders at Greengar have recently developed Smartboard, a collaborative note-taking app for mobile devices. It may not sound very exciting at first glance, but Smartboard allows Android and iOS devices to connect across platforms, in real-time.

“Everyone can share notes, at the same time,” says Truong. Greengar’s initial market for this product appears to be classroom use, but Smartboard could also be a useful app for the founder or entrepreneur on the go.

Oh, no. Not another fitness app...

Don’t panic, says Bia Sport CEO Cheryl Kellond, this one is different. Bia Sport is a social media platform linked to a hardware device--a sleek and stylish GPS watch--intended specifically to appeal to women.

According to Kellond, when it comes to running or triathlon events, “Women are out there to race with each other, but compete against ourselves.” For this reason, Bia Sport’s platform emphasizes community--not competition--and drives motivation through a supportive online community. If this sounds, well, like every other fitness platform in existence, consider Bia’s hardware device.

The GPS wristwatch comes equipped with an integrated safety alert for solo workouts. Meaning, a woman running late at night can press a "panic button" and have her location broadcast in real-time to family members and the relevant authorities. Bia Sport won the "People’s Choice" award for this year’s pitch competition.