SpinVox, a U.K.-based speech-to-text company that competes with SimulScribe and Jott in the market for visual voice mail service, says it's raised $100 million in financing.

Some media sites are reporting that the round values the company, which had raised a previous $100 million, at $500 million.

If so, the round shows one of two things: the value of startups that can conquer difficult engineering challenges and have valuable IP to show for it, OR  a fast-growing startup can find late-stage VCs willing to pay big to get into a fast-growing market.

Lots of telecom software companies have tried to solve what is easily the most annoying problem associated with voice mail: you can only access your messages sequentially. Busy people who live in a world of email and BlackBerries want to be able to view their message boxes all at once, so they can act on the most important ones immediately.

The massive funding round will give SpinVox, which says it has 6 million users, a war chest to sign up partnership deals with big wireless carriers. The company's multi-lingual technology, which can translate messages between English, Italian, French and German, have made it popular in Europe. 

The last time we had SimulScribe CEO Jamie Siminoff in for an interview, in late January, he called this  "freeing voice mail from its prison," and told us the company had revenue of more than $2 million in 2007 and is growing at 30% a month.

To see the early ad that generated SimulScribe a lot of buzz, click the video embedded with this post.