As popular as text messages have proven, one might wonder why there’s no service for sending instant voice messages.

The founders of Bubble Motion wondered that same thing in 2003, when they came up with a service that would allow cell phone users to send each other voice messages without making a call.

Today, the Silicon Valley-based startup announced a third round fundraiser, totaling up to $6 million, made possible by investments from new contributor Palomar Ventures and previous investors Sequoia Capital and Comcast Interactive Capital. Along with the new funding, Bubble Motion will also be adding Aepona CEO Al Snyder and Amanda Reed of Palomar Ventures to its Board of Directors.

Bubble Motion is calling its main product, BubbleTALK, a “’click, talk, and send’ messaging service,” enabling users to quickly and easily send short voice messages (called "bubbles") to anyone’s cell phone anywhere in the world. It makes sense for people who don’t want to get caught in unwanted long conversations. Bubble Motion thinks BubbleTALK, which is designed to work on any phone and network, is a no-brainer for mobile operators looking to bring in extra revenue.

The startup appears to already be taking off abroad, as a couple of its key customers are Vodafone in Egypt and Turkcell in Turkey. With additional partners in India, Malaysia, Indonesia, Thailand, and Hong Kong, Bubble Motion is currently available for over 225 million subscribers worldwide.

This latest round of funding comes a little over a year after the company raised $14 million in March 2008 from Sequoia Capital, Comcast Interactive Capital, and NCD Investors for a second round of funding. The company has now raised a total of $35 million.

Tom Clayton, President and CEO of Bubble Motion, says the team is “very pleased to have this round be oversubscribed, with our existing investors fully participating.” The continued support of previous investors along with the addition of a new investor signals a healthy future for the growing startup.